7 Gardening Danger Signs, and the Pests that Cause Them

Your well loved and stunning garden can speak to you – if you know her language. Foliage, fruit and even soil conditions can communicate with “Danger” signs. Pay attention and watch for these.

1) Holes in foliage

Smaller holes (almost like buckshot marks) mean flea beetles have been snacking. These tiny creatures are characterized by their size and habit of jumping from place to place (like a flea). They might not kill an established host plant, but when their larvae feed on the root system the plant is more susceptible to other problems.

Mulch your beds to deter the larvae from emerging. Some adventurous gardeners even vacuum the little pests off of the leaves – but this will have to be repeated numerous times (and who likes to vacuum anyway?).

If the holes in the foliage are curved and squiggly lines, you have leaf miner larvae chewing through. Use a pesticide or try something a little different. Purchase Diglyphus isaea wasps and let them loose in your yard. They’ll make a meal of the leaf miners.

2) Wilted Leaves

First off, this may be a sign of poor drainage, dry roots or improper sun exposure. Check those out before blaming any pests.

If everything else seems kosher, check the plant for aphids – probably the most common garden pest around. Tiny and often green bugs, aphids will literally suck the life out of the plant. They can be removed by hand, with a hard spray of water (over and over until you knock them off), yellow aphid traps and spot applications of insecticide soap.

3) Yellow or brown leaves

A change in leaf color may be indicative of a disease or fungus attacking the plant. A fungal problem called “Black spot” will actually turn foliage yellow – go figure. Rust and cankers both turn healthy leaves an unhealthy color. The best plan of attack is to remove the infected foliage (or sometimes the entire plant and burn or throw them in the garbage. Don’t compost.

4) Eggs Hiding Underneath Leaves

Here’s the good news – eggs hidden under the leaves of your plants can be removed. The bad news is that winter is often the best time to remove them. Be sure to pay special attention to areas that experienced pest infestations last season.

In spring look carefully under new leaves for any clusters of insect eggs. Remove promptly and toss them in the garbage. Also check the soil for snail and slug eggs. They’re round, clear and come in bunches, but don’t confuse your commercial slow release fertilizer pellets for them.

5) Snail Trails

If you spot glittery, almost silver lines in your garden, you have a snail or slug (or maybe a whole family). They hang out in the shade and damp spots and will cause plenty of havoc if left alone.
Pick the mollusk up one by one and get rid of them. Snail and slug traps can also work – try filling a shallow tin (like a tuna can) with beer, sink it into the soil a little and watch the pests go for a dip. Once you’ve caught them, relocate them far from the garden. Identify which plants and areas the mollusks flock to and patrol them regularly.

6) Sawdust at Plant Base

A pile of sawdust at the base of trees and plants is a good sign that carpenter ants have moved in. Although some argue that ants are beneficial – they remove diseased and rotted wood from a host tree – their residue is unsightly.

Try an ant trap or a commercial pesticide that target ants specifically. Baits work well to deliver poison to the colony, and if you can spot the nest try pouring boiling water over it a few times. Once you kill the queen, the rest of the colony will scatter.

7) Bite Marks on Tomatoes

You would be surprised what may feed on your tomato plants. Everything from possums to hornworms could be snacking. Try to determine when the bites are appearing. Larger critters usually nibble once the fruit is ripened. Set traps and let your dog or cat patrol the area. Try picking the tomatoes and bringing them inside to ripen. Hornworms can be removed individually and destroyed. They’re large enough to spot and don’t move quickly.

Watch for these danger signs in your garden and act quickly. Plan your attack and then design a defense to fight against garden pests and disease. Your plants and garden will thank you.