KATE COPSEY T&D Garden columnist
Any garden, from a simple tub to a large estate garden, can be plagued by pests and sometimes diseases.
Properly treating the issue is an important step in keeping these issues under control.
It is said that a shrub or tree is about 1/3 affected by a problem before you notice it. At this stage you really need to do something about it.
Walking the garden every day can help you spot problems before they take over the plant.
The opposite of this wisdom is that sometimes when the problem is insignificant, nature controls the problem without you having to lift a finger.
Stand 10 feet from the plant or shrub and ask yourself, “Can I see it?” If your answer is no, it might be worth not addressing the issue at this stage.
Buying a container of chemicals when just a few of your azalea leaves are turning brown or have holes is wasteful and often unnecessary.
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However, sometimes you need to act, and that means you need to know what it is before you treat it. Integrated Pest Control or IPM involves several steps:
1) Correctly identify the insect or disease
2) Find out the lifecycle of the problem
3) Treat before it becomes a bigger problem
4) Treat with the least toxic treatment first
This method of pest control will save you money at the department store and improve the overall health of the garden.
So – is it an animal, an insect, a fungus or a disease?
Animal damage is usually very obvious from clipped leaves – deer and rabbits are the most common culprits, and both can be treated by creating a barrier between your plant and the predator.
Rabbits can hop up and over a low wall but rarely jump a 24 inch fence. Placing a decorative fence around your plants or garden beds will protect the area.
Deer are more serious and can jump over 8 to 10 feet if necessary.
Luckily they need a run to jump those tall fences and in poor visibility the garden can sometimes be protected by a smaller fence with plants or raised beds on the other side.
Adding a pretty vine growing along the fence will also help confuse the deer.
For individual plants, a chain link fence around the plant or tree needs to be several feet from the tree to prevent the deer from reaching over and chewing on the tender new leaves. Cutting off stems and leaves is a sure sign of deer.
Insects vary in size from large caterpillars to tiny aphids, but both cause significant damage to leaves.
Although some insects, such as the azalea bug bug, are confined to just one plant, others have a very general diet. These are best spotted in the egg stage and treated with a horticultural soap that will prevent them from developing into adult insects like bean weevils.
Look for eggs both under the leaf and on top. Sometimes the eggs are obvious while other times the eggs are protected by a hard shell or liquid like the small spit bug. Both can be treated with soaps that stop the insect from developing.
Fungal diseases are more difficult to diagnose.
Sudden leaf browning can be a desiccation when the shrub is new or we are going through a drought. It can also be due to overwatering, which deprives the plant of nutrients in the soil.
There are also some diseases that are caused by a systemic problem like Verticillium wilt. These wilts are sudden attacks on the plant, browning the leaves within a few days. It is important to identify which of these problems is causing the browning and must be addressed as soon as possible as the shrub or tree could be killed within a few weeks if Verticillium is the problem.
So try to spot problems as you walk through the garden each day and make sure you’re treating the right thing. Then use the least toxic treatment for the problem before heading to the store.
The least toxic treatments include flushing plants to remove insects and eggs, using a soap treatment for small eggs, Bt for caterpillars, and fences for animals.
Some things need chemicals to treat them effectively, but there are very few that cannot be treated with organic or less toxic treatments.
Kate Copsey is a gardening writer, author, and speaker now residing in east Orangeburg County. Her book The Downsized Veggie Garden is available in bookstores everywhere and on her website www.katecopsey.com.