You can’t bear to toss your beloved old blue porcelain bowl set. And maybe that Michelin tire might come in handy again, so you should keep it. Although you might not use recycled porcelain bowls or apple barrels but rather terra cotta or woven pots, the simple concept of growing plants in pots or urns in addition to other objects, offers you a variety of enjoyable and creative ways to maintain and experiment with your garden.
The concept of container gardening existed before Boccaccio’s Isabella planted her lover’s noggin in a pot of basil: the Egyptians and Romans likely developed the idea.
Of late, container gardening’s popularity grew in southern California in the 1950s, and since then interest has escalated steadily. This brief guide is designed to facilitate decisions in planning and growing your garden in containers, since you will need to select the right containers and their ideal locations and plants.
Container Gardening Advantages
What makes container gardening so great? Consider the following short list of pluses:
Containers allow you to enjoy plants in areas where a traditional garden is awkward or impossible. Even with limited space in an urban apartment, you can grow fruits, vegetables, flowers and shrubs just about anywhere. Plants thrive on rooftops, decks, balconies, stairs and even on the stoop of your mobile home. And if you have a nice outdoor garden, you can vary your selection or save yourself the trouble of walking out to the yard on your sore ankle.
Container gardening also enables you to experiment with plants and to optimize or to control environmental conditions. If you live in New Hampshire, you can offer your sun-starved vegetables and herbs more light indoors or you can grow cacti or parsley in dry, well-drained soil that just doesn’t exist in your outdoor garden. And if you live in Arizona, you can shelter those Siberian crabapple plants.
Your hanging wire baskets and old tin buckets can restrain plants such as sage that spread quite easily in an ordinary garden by containing them alone or in reserved areas.
Additionally, you can grow different types of plants in one cordoned container in order to allow plants to exist in symbiotic relationships. Plants help each other to survive. For example, oregano repels insects that bother broccoli and enhances the flavor of beans.
On the other hand, containers allow you to offer special attention to your favorite fennel plant or cascablanca lily. If your particular herb sits on your windowsill next to your desk, then you can determine each day whether or not it needs a little more water or compost.
Plants in containers can be moved easily. Whether it’s shifting your pots of gardenias from your front porch to your backdoor during the rainy or cold season or transporting them to a new home, your plants can go with you.
Do you have heavy pots? Then garden dollies can transport those containers indoors during an early frost.
If pests infect your calendula, you can easily move and treat those containers with appropriate sprays without disturbing other plants.
Additionally, you can arrange containers so that plants can attract and repel insects or flies according to your needs. Some plants emit allelochemicals from their roots or leaves, which repel pests. For example, sweet basil can frighten away hover flies that bother your fennel. And beans attract insects that eat leaf beetles, which harm your corn.
Pots of blooming petunias make the most austere entrance or sparsely decorated balcony or deck feel warm and inviting. Or maybe you want to draw more attention to your seasonally decorated doorway or window? Use geometrical techniques, below, for that bare or busy wall, courtyard or patio. What’s more, if areas of your yard look scraggly or muddy, you can mask such eyesores with a large pot or two of colourful nasturtiums or strawberries.
Getting Started with Container Gardening
Now that we’ve piqued your interest, you ask: How do I get started? Do I want to get a bunch of small containers or two really big ones? Should they go in the bathroom or kitchen? Can I place pots around my regular garden? Would the pots look better on my deck or around my copper beech tree? Can I grow herbs and flowers or should I stick with one type of plant? Will someone trip over those small herb troughs near my narrow pathway or underneath my garden arbors? What complementary plant colors will look best in my sunny office?
Before you rush out to buy your needed plants, pots and tools for yourself or as a garden gift, consider the geometry of your garden.
Get out paper and pencil and jot down a few notes. Answer the above questions and any others that come to mind. Let’s say that after considering several questions you discover that you’re interested in herbs, but not necessarily in flowers. And you definitely want to grow the majority of your plants outside since you live in south Texas. However, since the summers can get too hot, you also want to be able to move your containers to a cool, shady spot of your yard or house as needed. You’ll also want to think about a niche where you can put those winter-weary tulip bulbs that are just waiting for spring.
Even if you start with just herbs, consider varying your choices slightly. If you grow parsley and thyme, cultivate potatoes or other vegetables because plants often enjoy one another’s company.
Start small. Even if you have visions of the Garden of Eden dancing in your head, you don’t want your garden to wind up looking like an unkempt graveyard. For some ideas, see our images of the most beautiful—and the oddest—gardens.
Now let’s do some real sketches of your ideal garden area.
Consider the Elements
Will your potted plants thrive best near your house or under your shady oak or sunny deck? Are your plants in a wind-and flood-safe area? Irrigation is important, too. Where’s your water faucet? Does your hose reach that particular area?
Also think about different types of groupings for your containers. Will your doorway look best framed with a set of two large potted ferns? Or do you want to encase the outside bay window with several hanging pots of red and yellow poppies? Sometimes scattered containers appeal more to the eye, but in other cases, one central plant surrounded by small herb containers looks attractive. This large central container could feature a variety of flowers such as daffodils, narcissi and violas while the smaller containers could each contain one type of plant.
If you prefer to keep your plants indoors, you might want to ensure that Toddler Joe can’t reach your poinsettia or that spilled dirt or water won’t harm grandmother’s cedar chest. Which parts of your house are warm and let in lots of sunshine? Where are the cooler, shadier rooms?
Containers for Gardening
Be choosy and creative in selecting your containers. First, each container should complement the plant aesthetically and functionally. For example, if you decide to grow strawberries, consider purchasing a terra-cotta planter that comes with special holes through which you can cultivate your fruit or herbs. And your small lilies may feel overwhelmed in a two-foot container, but your tiny bonsai will need taller, roomy holders. Our following section provides more details about types of containers.
Keep in mind that the size, material and shape of the container should be conducive to your plant’s health as well as to your surroundings. Experiment with your holders—buy some terra cotta and plastic pots just to get a sense of your preference. You may discover that blue glazed pots look better on your whitewashed deck than do wooden troughs.
- Grow Poles (in the image above) are an outstanding way to grow large amounts of vegetables or flowers in a very small space.
- Hanging baskets, often made of wood or wire, spotlight your petunias or geranium flowers. You should be careful that your indoor hanging pots don’t drizzle onto your lovely oak dining table, however. They should hold plants that won’t grow too heavy for the stand. Wrought-iron or other unusual stands can add appeal to your home, while also minimizing wood rot and insect havens.
- Window boxes are usually made of wood or plastic and are particularly attractive if you live in a high rise apartment with lots of windows.
- Raised beds are usually built into gardens or up against the side of a house or apartment. If these beds are built or placed against your home, then your roof can provide shade for plants, especially in sunny, warm regions. If you install your own raised bed, which can be designed in round, kidney or square shapes, plan the design so that it correlates with your landscape. However, plants in raised beds may not thrive in shady areas or too closely to tree roots.
- If you like wooden troughs or baskets, make sure that your wood is of a solid quality. You’ll want to also finish the wood with a plant-proof preserver. If you use barrels, make sure that the hoops are secure. Wood containers fare well in colder weather and also provide more insulation than do terra cotta pots.
- Your plants roots need to breathe, so they like terra cotta pots, which also hold warmth. However, if your cats, dogs or children romp through your house wildly or if you live in a cold climate where soil may freeze and expand, your terra cotta containers may not last.
- Glazed clay pots aren’t as porous as terra cotta, though you can choose glazed colors that match your decor. These pots are traditionally used in Japanese gardens.
- Stone containers add a natural effect to your house or garden, but are often difficult to move. They also can break fairly easily.
- Plastic pots often resemble terra cotta containers and can be moved or cleaned more easily than terra cotta. However, plastic doesn’t allow your plants to breathe freely.
- Sunken containers work well especially for plants like mint that spread easily. You can either bury the whole container in your garden or embed the rim to restrain the plant.
- Don’t forget those eclectic containers like wire baskets, old-fashioned metal bathtubs and rickety wheelbarrows. They make great holders, too.
- And no matter what type of containers you purchase, you’ll need some fail-proof saucers to capture that loose soil and dripping water that escapes from the bottom of any container. Although plastic saucers may not match your glazed pots, they don’t get damp as do terra cotta ones.
Vegetables and Fruit for Container Gardens
If you dwarf your rootstocks, you can grow apple trees in containers.
Cucumbers need lots of water and a large container.
Varieties of cherries do especially well in sandy soil and containers that are about 18 inches deep.
Use a tough container to restrain those fig roots.
Eggplants do well with frequent fertilizings.
Lettuce needs frequent feedings and waterings.
Summer squash does especially well in containers.
With the assistance of stakes and deep holders, many varieties of tomatoes do well in containers.
Spinach likes organically rich soil.
Cabbage grows well from seed and likes rich compost.
Cauliflower heads need lots of room, and small varieties do best in containers.
Most bean types don’t like frost, so bring your containers indoors in the winter.
Radishes grow quickly and easily.
Blueberries grow nicely in containers, but need warm summer in order for berries to ripen.
You can select from a variety of potato types, and they grow easily.
Turnips like full or partial sun. Harvest your turnips promptly.
For your containers, be sure to use a dwarfing rootstock such as Pixy.
Even some shorter varieties of corn such as Sugar Buns and Quickie grow well in containers.
Edible Plants and Containers
Most of the plants so far are aesthetically appealing, but not necessarily edible. Fruits, vegetables and herbs provide wonderful aroma and taste, and many varieties perform well in containers. What’s more, vegetables, herbs, flowers, and other plants grow well together. You can even use cordoned containers or troughs that grow vegetables and herbs. Try planting garlic with roses and nasturtium with cabbages. You can even mix six or seven herbs together in a wooden trough or large terra cotta pot.
Fruit plants such as apple trees or strawberries require lavish attention. They attract pests and need to be pruned and fertilized. Before you take the plunge, consider these and other questions: How much room do you have for your fruits? Do you want to focus on berry plants? Or are you more interested in apples or apricots? For example, if you grow apricots, your trees eventually will outgrow your containers. So you might want to make sure you have permanent spots for these larger plants. However, other fruits such as figs can be contained very nicely with constant pruning. If you choose to specialize in fruits, you’ll need to ask even more detailed questions at your local nursery. Or join a fruit gardener club. You also might consider obtaining texts that focus specifically on nurturing your particular fruit choices.
Consider this limited overview of a few fruit selections to obtain a better sense of requirements. Blackberries are versatile, but strong. Find a sturdy tub or barrel and plant thornless varieties such as Navaho. You’ll need to let the canes grow several feet during the summer before you pinch them back. Constant pinching and pruning will result in good fruit in a few years. Peaches and nectarines may prove more doable, especially if you grow them from dwarf rootstocks. You’ll need to protect your peaches from excessive damp conditions, though they don’t mind hard winters. They need warm summers, too.
The good news? Your cucumbers, thyme, sage and cabbages are pleasurable and successful plants to grow in containers. One advantage of using a container for vegetables and herbs is that you don’t necessarily need to worry about straight rows and tidy raised beds. And you can shelter plants during weeks of intense summer heat. But you’ll need to diligently water, fertilize and provide light. Vegetable and herb plants are needy creatures.
Your vegetables and herbs need a lot of sun even if you grow them in containers. Consider planting them in wooden or concrete troughs so that you can arrange adequate drainage. For example, you can replace raised beds with sunken cement blocks; several varieties exist and these blocks don’t rot.
Hungry plants, aren’t they? Vegetables and herbs often profit from quality organic soil with plenty of compost. You will also need to build up the soil each year. Start composting if you haven’t done so already.
How many vegetables are enough? Refer back to your container garden plan, though you might consider starting with small quantities of vegetables such as carrots, broccoli and beans. Once you’ve cultivated a few successful shoots, add some more beans or other vegetables. And don’t forget to consider symbiotic relationships, see below, or organic varieties.
If you are willing to grow a great variety of smaller vegetables in containers, then you’ll enjoy providing your vegetables with care specific to their needs. For example, Dwarf French beans look nice in hanging planters, since their pods can hang over the sides. Other beans such as Purple Teepee have colorful pods. If you don’t have a lot of room, try growing radishes, since they don’t mind crowded conditions, whether in hanging pots or in cordoned containers. And they’re edible just three weeks after the seeds sprout.
Dwarf varieties of cabbage and even corn can grow well in large containers. If you really like cabbages, you can take a second crop off of each cabage plant by cross-cutting the stem of the first head in order to grow smaller heads. Corn varieties such as sugar buns (for a sweet flavor) may need a barrel-sized container. Potatoes will require a very large and sturdy container. Start with potato eyes set in about a foot of soil. When you see sprouts, cover the shootings with grass and continue this process of layering and watering until harvest time.
You forgot to purchase that thyme at the the store for your steak marinade? No worries: just reach up and pluck some thyme from your hanging basket. You could also keep a container box full of herbs such as chives and winter savory right outside your kitchen door. Most compact herbs grow well together, so you needn’t worry if you plant all those marjoram, thyme, sage and rosemary plants together in one huge container.
Many herbs grow easily from seed, so easily that they sometimes are considered plain weeds. That’s why they often do well in containers so that you don’t have herbs sprouting all over your yard. In cases of herbs such as sage, you can propogate plants from seed indoors. Since such seedlings often need dark, warm, moist and consistent conditions, they thrive well in small containers indoors. You can later transplant or move your herbs outdoors once the shoots have established themselves.
Which type of parsley is best for your garden? Curly leaf, Italian (flat leaf) or hamburg? The latter grows mostly underground; you’re more likely to experiment with Italian or curly leaf parsley. Parsley takes at least six weeks to germinate, so you’ll need a little patience and quite a bit of water and fertilizer. Consider planting parsley and carrots together, since this herb repels carrot flies. If you’re starting your first container garden, you might also consider growing varieties of mint, since it grows easily and you can choose from a plethora—apple, orange, ginger and curly to name a few. Since mint cross-pollinates easily and therefore loses its flavor, it serves as a prime container plant. You can prevent cross-pollination and decorate different parts of your home with small holders. Unlike parsley, however, mint cannot be propogated from seed but rather from cuttings. Mint also prefers larger 1-foot containers. Once your mint grows, it can be harvested at any time, so you can enjoy this herb early and often.
If you’re hungry for more details on herbs and other edible plants, see our lists of vegetables and herbs.
Now that you’ve planned your geometric outlay, studied facts about containers and a variety of plants ranging from bougainvillea to winter savory, you’re ready! Soon those terra cotta pots of dwarf pomegranates and orchids will grace your shady deck or bedroom windowsill with color and fragrance.
Herbs for Container Gardens
Sage, a perennial plant, loves lots of sun in soil that drains well.
Rosemary craves attention, the sun and lime-rich soil.
Moist, rich soil and plenty of sun and trimmings or “haircuts” will result in healthy chives. Common chives are mostly evergreen in mild climates, but become dormant in harsh winter regions.
Dill or dillweed, a popular annual, loves fertile garden soil and lots of sun. Dill is night-length sensitive, so your dill and its flowers will grow steadily if you plant seeds in the early spring.
Many types of this thirsty, tender, tropical annual exist, but most varieties of basil grow quickly and easily in warm soil that should be fertilized lightly two or three times a season.
Saw Palmetto appreciates well-drained but moist soil and lots of sun. This tropical palm attracts bees which make honey from its flowers.
Common thyme, which adds great flavor to meat dishes and soups, doesn’t mind being neglected a little bit, since it thrives in light, warm and fairly dry soil.
Cilantro, a self-sowing annual, is wind-shy, but thrives in just about any type of garden soil.
Chamomile enhances the growth of any nearby plants. This herb also loves full or partial shade or sun and moist, well drained earth.
You can buy and plant garlic cloves from your local supermarket if you don’t want to acquire cloves from someone else’s nursery. Garlic likes fertile soil and full sun, though it can survive in some shade.
Mint prefers moist soil and shade and a little sun.
Oregano, which enhances the flavor of your beans in your garden, also repels insects that bother your broccoli.
The herb lemon balm likes just about anything: full sun or lots of shade and this plant can be grown from seeds, cuttings or divisions.
Calendula craves rich well drained soil and partial shade, since it prefers cool temperatures. This annual steadily grows to about to about two feet.
Several varieties of this semi-hardy perennial exist, but all dislike frost. Lavender, which makes a nice edging or hedge, prefers plenty of sun and loose, fast-draining soil.
Catnip prefers sun or partial shade, but if you grow your catnip in full sun, the plants will be sturdier and shorter.
Anise needs consistent watering, though you mustn’t overwater it. Plant in full sun and make sure the soil drains well.
The annual herb Nasturtium prefers sun and regular waterings, but does not need a highly fertile soil.
This shrubby perennial enhances the growth of surrounding vegetables and prefers sandy loam and full or partial shade.
Fennel (Sweet Florence)
Sweet Florence fennel, which resembles dill, does not grow as tall as common fennel, but this variety likes plenty of sunlight and well-drained, fertilized soil.
Summer savory craves rich, loamy soil and lots of sun.
Sweet Marjoram can be propagated easily from seed or cuttings indoors or outdoors.
Over 200 varieties of geraniums exist. Most scented varieties prefer well drained soil and at least 6-7 hours of sun a day, but cannot withstand excessive heat.
Parsnip prefers fertile soil that does not bake, though this plant sometimes is difficult to grow.
Sesame craves well-drained and fertile soil, but don’t add too much nitrogen.
The tropical plant ginger is highly adaptable.
Flowers for Container Gardening
Many successful container flowers are either annuals or perennials—they either undergo their full lifecycle from seed in one growing season as annuals or they bloom in the second year and last for a few years as perennials.
Gardeners often cannot resist annuals since these marigolds and petunias add cheerful color to any setting. Petunias, for example, thrive in almost any type of container and are easy to grow, though they do not love intense heat every afternoon. Zinnias, however, succeed in hotter climates, and you can even purchase the Thumbelina variety. If you crave color during those mild winter months, then you’ll like primroses, which bloom from winter to spring.
Annuals are so easy. Why try anything else? For one, flowering perennials last longer than a few months or so, the duration of time that most annuals last. Additionally, perennials can grow larger over time so they can fill a nice ample niche of your deck that might look overwhelming with a small set of annual flowers.
Your perennials will need more year-round attention: you’ll want to fertilize them occasionally even during the coldest winter months. And you may need to trim those scraggly stems. However, this pruning and fertilizing care will result in hardier perennials come spring. And you won’t have to trudge to your local nursery for a fresh round of seeds. In some cases, you can pinch off sprouting flowers so that even more flowers or little plants grow.
For example? Bird of paradise plants need frequent feedings throughout the year, but you’ll receive an abundance of color in return. And varieties of daylilies will suit your particular climate. You can also divide daylilies easily to grow new plants. Or you can snap off spent flowers to encourage growth. Geraniums, one of the best-known perennials, maintain a consistently cheerful look throughout the year, so they only need occasional repottings or pinchings of flowers.
Bulbs are somewhat like annuals—they may bloom profusely for one season—but you can save and plant bulblets. Tulip bulbs, for example, can be planted in the fall with tips just at soil level. If you water regularly, then you should have a sensational show of color in the spring. Daffodils are even easier to grow than tulips and you can cultivate them to gain a longer season of blossoms.
If you want hardier, longer lasting plants, then consider growing shrubs and trees. Some flower, others don’t, but since these plants are contained, you can plant them at almost any time except during very hot weather.
Dwarf forms of crape myrtle, which do best in containers, may need occasional prunings of twiggy growth during dormant seasons, but this tree loves warm summers. The hotter the summer, the brighter the clusters of flowers seem to get. Bushy forms of bougainvillea such as Temple Fire also thrive well in containers and in warm climates. Bougainvillea trees need protection when temperatures sink below 30 degrees F, but you can prune this tree to shape.
Other distinctive varieties of container plants such as cacti and ferns also may add style or interest to your garden. Cacti need even less water during cooler weather and very few feedings save during potting time. Ferns crave more water and a far richer soil than do cacti, but they do not react well to frosts or hot winds.
Other interesting assortments of plants such as bonsai and bamboo exist, and you may even want to study and create specialized areas such as Japanese or bonsai gardens if you are particularly interested in this type of container gardening.
Do you want to learn more about growing other varieties of flowers such as African daisies or poor man’s orchid? Consult our list of different types of container flowers.
List of Different Flowers for Container Gardens
Lily of the Nile
Even the dwarf size, Peter Pan, is ideal for smaller containers.
These perennials are an autumn favorite.
This asparagus sprouts red berries and needs to come inside during cold winters.
Bird of Paradise
Bird of paradise needs feedings throughout the year, but you’ll receive an abundance of color in return.
You can divide daylilies easily to grow new plants.
African daisy resembles the common daisy and needs only a shallow holder.
Begonia does well in hanging baskets.
Ground ivy has small green leaves edged with white.
Lantana flowers can change color as the flowers mature.
These are popular summer flowers.
These flowers are about two-inches in diameter.
Zinnias boast a variety of colors and types.
Iceland poppies fare well with pansies as companions.
Marigolds come in shades of yellow and orange and mix well with other annuals.
Pansies/violas blossom early in the spring.
These snapdragons don’t necessarily do well in bouquets since stems only are about a foot long.
The Christmas Rose hellebore blooms in the winter, though other varieties appear in springtime.
Lamb’s ear, an evergreen, has silvery hairs on its leaves.
Rock jasmine flowers in May or June, and bodes well in rock gardens.
Plants for Container Gardens
You’ve got a running list of garden tricks, pots and tools. And so you just need the plants. Again, a word of caution: resist loading your car to the brim with ferns and bamboo shoots; start with a few of your favourite things—pansy and marigold seeds and rosemary and coriander. And then in a month or so, you can sprinkle some broccoli seeds. Thousands of types of container plants exist, and the following information is by no means exhaustive, though it should give you a solid sense of what types of plants with which you could start.
Again, consider your climate and garden layout. Read the directions on seeds packets. Ask questions at your local nursery. Submit inquiries online to your virtual nursery or favorite gardening website that helps you to discover whether or not nemesia plants enjoy the company of violas (they do).
We have many different pages consisting of links to different flowers, herbs, and other plants that are great for container gardening. And don’t miss this site with organic gardening tips and a guide to growing many herbs, fruits and vegetables.
Shrubs and Trees for Container Gardens
Dwarf forms of crape myrtle, which do best in containers, may need occasional prunings of twiggy growth during dormant seasons, but this tree loves warm summers.
Bushy forms of bougainvillea such as Temple Fire also thrive well in containers and in warm climates.
Bulbs for Container Gardens
Daffodils are even easier to grow than tulips and you can get a longer season of color if you want a longer season of blossoms.
Snowdrops appear early in the spring.
You can choose between Dutch and Roman varieties of hyacinth.
Irises need to be planted in September.
Bluebell can either have bell-like or star-like flowers, depending on which type you plant.
The tiger flower appears at the end of summertime but needs to be planted in April.
Odds and Ends: Additional Things to be Planted in Container Gardens
Dwarf pomegranate grows smaller versions of the red fruits.
Black bamboo grows to about 6 feet.
Aloe comes in a variety of sizes, and grows well in warm regions.
How to Take Care of Houseplants
Welcome Your Houseplants Indoors
Proper care, plus the right environment, will give you a successful season indoors.
Back in the days before central air and heat house temperatures and humidity were just about perfect for most house plants. But today, with our central systems, proper growing conditions have all but vanished from the home. This does not mean, however, that indoor gardening should become a lost art. With a few alterations, there is no reason why you cannot have plants blooming on your window sills while white, powdery snows are blowing from the roof tops.
Correct Lighting for Houseplants
As you possibly already know, lighting is of utmost importance in indoor gardening because it furnishes energy for plant growth. Even those plants that thrive on filtered light will not set buds without some sun. This is especially true of African violets which actually welcome the weak winter sunlight.
Because most house plants do need sunlight in winter, they do best in a southerly exposure. An east window will do for plants that normally do not need direct sunlight. It must be remembered that plants will not grow or bloom as they should unless the amount of light they receive is about equal to that of their natural home.
In many houses, large foliage plants are often used to set off pieces of furniture along inner walls or in dark hallways. To keep these foliage plants healthy and growing, place a 150-watt incandescent bulb within 4 feet of each. The light must be turned on throughout the day and extinguished after sunset.
I am aware that sometimes it just isn’t possible to grow plants on window sills in certain homes. The windows may be too small or too high, or the decor may not allow it. If this situation exists in your home, do not fret. You can still garden indoors by purchasing plant-growing stands already equipped with proper lighting. These are inexpensive and are excellent for all small plants that-love filtered sunlight, such as the African violets, caladiums and gloxinias. Because of the built-in lighting system, the plant stands may be placed anywhere in the house.
Humidity and Houseplants
Humidity is a governing factor in the health of all plants. If the plant is expected to do its best, the relative humidity surrounding it night and day must be the same or close to that of its original habitat. When a plant originates in a definite amount of humidity, it adjusts its life processes to that particular amount of air moisture. All jungle plants that prefer filtered light demand a humidity as high as 90 per cent; subtropical plants, 50 per cent; temperate zone plants, 45 per cent; and desert plants, 5 per cent.
The most difficult problem facing today’s indoor gardener is maintaining the right relative humidity for the different kinds of plants he or she wishes to grow. Humidity is far more important than one might think, and cannot be shrugged off lightly. Low humidity is disastrous to plants — especially those of the jungle. If the surrounding air remains hot and dry, evaporation takes place very rapidly, drying off leaves and causing more rapid transpiration. (Transpiration is the escaping of moisture through the pores of the leaves.) A plant has been so constructed that there is a balance between the amount of moisture absorbed by the roots and the amount evaporated from the foliage. Plants will wilt in low humidity even though the soil contains sufficient moisture. If wilting continues over a long period, the plant will die.
Too high a humidity is not dangerous to most plants, except those of the desert. It causes them to become leggy and spongy. To maintain sufficient humidity, place pots on pebbles above the water level in shallow trays. Or, if your plants are on glass shelves over a radiator, keep a pan of water constantly on it. Enough water will evaporate to maintain a decent humidity reading. Several plants in a group will aid humidity by transpiration. Frequent spraying of the leaves with water will also go a long way toward keeping humidity at a high level.
Since all plants do not require the same amount of humidity, separate your plants into groups according to their air-moisture requirements, then keep just that one particular group in a suitable window. That way you can better control the humidity each group needs.
Inexpensive humidity indicators are great aids to indoor gardening. They will give you the exact humidity reading of the air around your plants, thus warning you when more moisture is needed. You will find that one water spraying can increase the humidity as much as 10 per cent in a few seconds.
Temperature and Houseplants
The third important growing factor in plant growth is the air temperature. Each type of plant demands the kind of temperature it originated in. Jungle plants require higher temperatures than other plants, although temperate zone and desert plants can withstand 90 to 100 degrees for a short time without harm. Low temperatures are actually the demons that do plant growth real harm.
In the plant’s natural habitat, temperatures naturally drop at night, and plants have adjusted their life processes accordingly. During the day, with energy from the sun, plants manufacture carbohydrates from the soil and water, and extract carbon dioxide from the air. When darkness falls, photosynthesis becomes an impossibility. Plants need food for growth so they turn the starches they manufactured during the day into sugars, and use them to build new cells.
Tropical plants can withstand a minimum of 65 degrees at night; subtropical plants, 55-60; temperate zone plants, about 45 degrees; and cacti will endure any temperature as long as it is above freezing.
Like people, all plants are healthier when they sleep in a cool room. The drop in temperature at night serves to stimulate the action of turning starches into sugars for growth. If temperatures remain steady for 24 hours, this process is not stimulated enough for proper growth and bloom.
If your plants remain on the window sill, surrounding air will automatically become copied by the pane at night. But if they are located where temperatures remain constant, remove them to a cooler spot at night, or lower the heat in the room.
As you become more accustomed to growing plants indoors, you will find that there are some plants that defy all rules pertaining to their particular group. For instance, camellias, which in reality are jungle plants, will drop their buds if temperatures rise above 65 degrees. This does not mean that you cannot enjoy growing these demanding plants in your home. Use an indoor thermometer to locate the warmer and cooler spots in your home, then station these plants where temperatures are suitable.
As winter creeps on, you will find that low temperatures, and not high ones, create problems at night. For instance, night temperatures may drop dangerously below the 65-degree mark during cold spells on the sills where African violets are growing. Protect them by drawing the shade, by installing a storm window, or by placing several thicknesses of newspaper between the plants and the pane. Hang a thermometer in each window where plants are growing, and do your best to maintain the right night temperature for each individual group.
Proper Potting Soil Mixtures for Houseplants
To keep your plants healthy and happy, grow them in the kind of soil they are used to. One mixture will never do for all.
The jungle floor is not a thick layer of black topsoil as one might think. Because growth is so intense, organic matter is used up before it can turn into rich soil. The upper crust consists only of a thin layer of vegetable matter in the process of decay. Taking this into consideration, leaf mold and sphagnum moss are the chief constituents of jungle soil. A good potting medium for jungle plants should consist of one part organically enriched garden loam, two parts leaf mold, and one part coarse sand. If your soil is sandy like mine, use one part garden loam, one part sifted compost, and two parts leaf mold. The soil pH should be 5.5 or under.
Temperate Zone Soil
Temperate zone plants need darker soil rich in humus with a pH near neutral (7.0). The soil mixture I use consists of two parts garden loam, one part sifted compost, and one part leaf mold. Use one part sand if your soil is heavy.
The desert plant group, which comprises all forms of cacti, prefers a soil mixture of one part garden soil, two parts sand, and one part coarse gravel. The pH should be neutral or slightly alkaline.
Since the roots of plants that are potted cannot go off in search of food, I find it beneficial to add one table-spoon of ground phosphate rock, one of potash rock, and one of bone meal to each 6-inch pot when potting or repotting.
Pots to Use for Houseplants
It may surprise you to learn that the type of pots you use have a great deal to do with the health of the root systems. If at all possible use only clay pots. They have their own cooling system because moisture is drawn from the soil through the side walls by force of evaporation. Actually, the clay pot is capable of evaporating twice as much through its walls than from the surface soil. This beneficial evaporation has a cooling effect on the soil and the roots, resulting in healthier, happier plants.
How Much to Water Houseplants
Watering house plants requires a skill that can be developed quickly if the needs of the different plants are learned. In outdoor beds where plants grow all summer, you will notice that the soil remains moderately moist at all times. After rains drain away and the topsoil begins to dry, it absorbs moisture from the subsoil through capillary attraction. In such earth, only the soil particles are damp, with a multitude of air spaces in between. Roots are designed to absorb moisture and plant nutrients from the moist particles, and oxygen from the air spaces. If the soil is too wet, these air pockets are filled with water, thus shutting off the needed oxygen supply and hampering the natural growth processes.
I have found that it is not wise to water until the surface soil feels dry. Then, instead of watering from the top, I find it better to plunge the pots in water to within an inch of the rim. When the surface becomes moist, I remove them to the drain board to allow the excess water to drain off, then replace them on the sill. Three such dunkings a week are usually sufficient for my plants.
In reality, no one can say how often to water a house plant. It depends largely upon the relative humidity and the type of pot the plant is growing in. Clay pots may need watering every day, while others may get along with a watering every other day.
Above all, do not overdo the no-watering bit to the extent where the plant withers. Such a plant will take several days to recover after it finally is watered. Or, if water has been withheld too long, it may never do so.
If you care to take the trouble, there are a number of ways in which you might cut down on watering, thus saving time and root systems. First off, of course, make certain your soil mixtures contain plenty of humus to retain moisture. Secondly, if possible, use sheet moss as a mulch. This must be gathered in fall. I like to use green moss from beneath my weeping willows. After removing as large sheets as possible, I soak them in water for a few moments, then cover the entire soil surface of each pot with it. African violet lovers who lose plants because the leaves are burned by concentrated salts on the rims of the pots, will be happy to learn they can prevent this by draping green moss over the rims. African violets actually love the cool, moist texture of the moss.
Another good point to remember while watering is never to use cold water. It slows down the activity of the plant. Although water is in abundance, the chilled plant will wilt because it does not have the power to absorb enough moisture. Always bring the water to room temperature before giving it to the plants.
You can also cut down on watering by placing a porous clay pot in a non-porous container. There should be at least one inch of air space between the two. This will not interfere with the evaporating cooling system of the smaller pot, and will enable it to better resist the effects of a dry, overheated house.
Wardian Case – A Terrarium for Indoor Container Gardening
A Wardian Case also known as a plant terrarium.
If you’ve never used an indoor terrarium to grow houseplants indoors, then don’t! Because you might get hooked, it is so easy and enjoyable. The glass case holds in moisture, so you can literally go weeks or sometimes months without watering your plants.
Terrariums, also known by the term Wardian Case because of the English inventor, are terrific for humidity-loving plants like ferns and African Violets. But almost any type of houseplant will thrive inside a terrarium, so they are a great gift for people who never thought that they could keep a houseplant alive.