By Matt Gibson
Lupine is anything but subtle. It is a vibrant plant decorated with tall, showy flower spires that come in a dizzying array of shades. Lupine appears in various hues of purple, pink, red, white, and yellow lighting up garden beds all over the world in the springtime with its narrow towers of dense flowers. The leaves of the lupine plant look similar to palm tree leaves, each sporting seven to ten leaf segments.
The Lupinus genus is made up of hundreds of ornamental species which are highly regarded by wildflower enthusiasts. Wildflower tours and festivals all across the country center around the blooming of native lupine varieties. The lupine cultivars that are grown in the garden, on the other hand, are typically hybrid crosses of the native species that bloom in the wild, bred by horticulturalists to improve flower colors and vigor.
The most famous lupine hybrids commonly grown by modern gardeners, are the Russell Hybrids, which were created in the 1930’s by an avid gardener, horticulturist, and plant breeder named George Russell. Mr. Russell gathered and used only the seeds of the best lupine plants that he created by using cross-pollination. Mr. Russell’s hybrids are amongst the most beautiful lupine available. Each plant sends up tall flower shutes that are decorated with large swatches of bright, vibrant colors. Mr. Russell left gardeners with a hybrid variety for every color in the rainbow, and his cultivars are to this day, amongst the most beautiful lupine varieties in existence.
Lupines are very easy to grow. All they need is a suitable growing spot that contains a slightly acidic, nutrient-rich, well-draining soil and full sunlight exposure. Other than that, the only thing that they need is an occasional deadheading to encourage additional flowering. Taller varieties, like the Russell hybrids, should be provided with a garden stake so that they have help staying vertical. Lupines will suffer in hot, humid conditions, and should be brought indoors during the midsummer if possible, to get away from the powerful summer sun.
Lupines were not always beloved. Lupines were named after the latin word meaning wolf, because people believed that they greedily used up all of the nutrients from the soils they grow in. In fact, they couldn’t have been farther off, as the lupine plant is from the same plant family as peas, and like peas, the lupine plant is known for fixing nitrogen levels in the soil that surrounds them.
Varieties of Lupine
Arctic Lupine – The arctic lupine cultivar is native to the arctic regions of northwest North America, from Canada to Alaska, producing flowers that range from purple to blue. The arctic lupine is well-suited and well-adapted to northern climates and low-nitrogen soils
Arroyo Lupine – The arroyo lupine is also known as the succulent lupine, and the hollow leaf annual lupine, and is primarily found throughout the state of California. Considered the largest native annual lupine variety, the arroyo lupine is commonly grown in garden borders and in container gardens. The arroyo lupine’s purple-blue flowers make it one of the most popular cultivars. One significant drawback of the arroyo lupine is its tendency to be highly toxic and poisonous. If you have dogs, or other curious pets, don’t allow them private access to these lovely ornamental plants, as they could become severely ill if they were to eat any of the plant’s leaves, stems, seeds, or roots.
Blue Pod Lupine – The blue pod lupine is the dominant parent species that was used to create the Russell Hybrids. The blue pod lupine is considered the tallest and most beautiful natural perennial cultivar available to gardeners.
Large Leaved Lupine – The blue and purple flowers of the large leaved lupine are native to the northwestern United States. This variety is grown for its ornamental value, and for its ability to naturally improve poor quality soils.
Riverbank Lupine – The riverbank lupine has the most uses and benefits among the lupine flower species. Grown for its ornamental value, to improve soil quality and nitrogen levels in depleted soils, for erosion control, and for its robust and refreshing fragrance.
Russell Lupine Mix – This is not technically a variety of lupines, but a seed mix that contains a random mix of the various Russell Lupine hybrids. Plant lots of Russell Lupines together for the upcoming season. Plant them in groups or spread out throughout the garden for tall (three foot) blooms and a random mix of bright, vibrant colors that show off the true range of colors that are available when growing lupines.
Texas Bluebonnet – The state flower for the lone star state is the Bluebonnet. In the state of Texas, it is against the law to pick them or mow over them, but it is perfectly acceptable to plant bluebonnets all over the state. One place bluebonnets are absent from, however, is Texan flower gardens. For some reason, the deep-blue flower spikes that grow in the wild all over the state (most prolifically in the hill country) are not a common sight in Texas flower beds.
Growing Conditions for Lupine
Lupine shrubs thrive in full sun locations. The ornamental plants can survive in partial shade, but will produce far less blossoms in shady locations than they would in full sun. Lupines grown in deep shade locations will not produce flowers at all, but will focus entirely on growing foliage instead. If your lupines are getting too much shade, try cutting back surrounding shrubs and trees which are casting their shadows on the sun-thirsty plants.
If the temperatures get too high, or they receive too much sun, especially in the first few weeks of summer, Lupines can occasionally fail to flower at all. This is not to suggest that lupine plants don’t like the sun. They just enjoy a cool day of light sunshine over the sweltering, heavy summer sunshine.
How to Plant Lupine
Lupine plants and seeds are fairly easy to find, and they are available to gardeners as annuals, or perennials, and can produce both annual and perennial crops. Potted lupine plants are usually perennials that come back each spring, living and blooming for many years, instead of dying away after just one growing season.
If you purchased a young lupine plant, or plants at a nursery, or ordered one online, plant it as soon as you are able in your garden beds. Before planting, amend the soil for your flower garden with lots of organic matter to boost nutrient levels and improve moisture retention, as well as some sand to improve drainage. Don’t let your mulch layer, or any other type of organic material sit against the crown of your lupines, as it will cause crown rotting. After planting, water new plants thoroughly to help ease the transition into their new homes.
If you are to be planting lupine seeds, they can be planted out in the garden anytime in the first few weeds of spring. For better results, wait until the late spring to plant, so that the seeds will overwinter and bloom in the next spring. Prior to planting, soak seeds for 24-48 hours to help soften up the seed coat for easier germination.
If you don’t have time to soak the seeds, give them a good head start by roughly abrasing them between two sheets of sandpaper. Sprinkle seeds and top with about one-eighth inch of soil. Press the soil down gently to remove air pockets and insure seed to soil contact. Water well just after planting and continue to water lightly until you see sprouts. Germination should take around 10 days.
Care for Lupine
Lupines need regular watering and proper drainage. Provide one inch of water per week in dry conditions. Mulch to improve moisture retention and keep the soil cool in hot climate areas. No fertilizer is necessary for lupines, and excess fertilizer can actually keep the plants from blooming, causing them to focus solely on leaf growth instead. If you have high alkaline soils, however, you can use an acidifying feed to lower the pH [https://www.gardeningchannel.com/add-nitrogen-garden-soil/].
Deadhead spent flowers to encourage additional blooms and to keep unwanted volunteers from moving in and taking over. Deadheading will also keep lupines from developing seed heads, which will force the plant to focus more on root and leaf development, making the plant denser and more vigorous.
How to Propagate Lupine Flowers
Lupines can be propagated from seed, cuttings, or divisions. If you are growing your lupines from seeds, you will need to help germination along by stratifying the seeds. One way to stratify seeds is by using a seven-day cold treatment, putting your seeds on slightly damp paper towels and storing them in a ziploc bag in the fridge for seven days. A 24-hour warm water soak is another way to help soften the seed coats. Treated seed can be directly sown into soil anytime during the spring or summer up until the first of August. If you are planning to skip seed stratification, plant untreated seeds into the soil between September and November.
If you are growing lupine from seed, expect blooms in the first year. Deadhead spent blooms to extend the plant’s blooming time. Feed plants once per month with a balanced organic fertilizer to keep plants healthy and to get the biggest blooms out of your lupines.
To grow from cuttings, cut a stem all the way down to the trunk and set it in moist, well-drained sand, or some other well-draining medium suitable for propagation. Keep cuttings covered during this time, only exposing them to air for a few minutes per day. Once roots develop, move cuttings into large pots that can be moved outdoors in their pots so as not to disturb the taproots. Do not transplant without the pots, as the lupine’s long taproots are especially fragile and essential to plant health.
Lupines should be divided every three years to keep plants healthy, moving divisions into separate pots, or directly planting them into their new garden locations just after division.
Garden Pests and Diseases of Lupine
Lupine flowers are a bit sensitive to struggles with garden pests and plant diseases. Review the list in this section of symptoms and remedies that gardeners of lupine should be familiar with so you’re ready to face whatever comes your way.
Aphids: Tiny aphid insects hang out on the underside of leaves, where they feed on the moisture inside foliage. You can tell when a plant is battling aphids because the bugs are visible on the backs of leaves, and the foliage of affected plants is wrinkled, curled, or distorted in shape. To fight back against aphids, you can try knocking them off the plant with a jet of high-pressure water, which is effective because they’re so small. You can also make a homemade spray to treat plants with out of one liter of warm water, four or five drops of dish soap, and a tablespoon of neem oil. Be vigilant for signs of aphids, as they can spread cucumber mosaic virus, a fatal disease.
Brown Spot Fungus: If you see brown patches on lupine foliage, the culprit may be brown spot fungus. Pull any affected plants out of the garden and discard them carefully. As with any diseased or infested plant material, do not use in compost.
Powdery Mildew: When rain is heavy, powdery mildew can be a problem in the garden. The first sign of powdery mildew tends to be white areas on foliage that look like talcum powder. Use clean, sterilized gardening shears to snip off any signs of powdery mildew on lupine foliage. As long as you don’t remove more than two thirds of the leaves, they will grow back.
Growing lupine is a joy for beginning gardeners and seasoned gardeners alike. The eye-catching blooms of this versatile ornamental are second to none. Now you are equipped with everything you need to know to grow lupines successfully, it’s time to put that knowledge to work.