Tag Archives: pests

Spider Mites

That’s a good question
If you notice the leaves on some of your plants appear stippled or flecked with pale dots and have fine webbing, especially on the undersides, you have a spider mite infestation. These pests thrive during dry weather and their populations can get out of hand by August.

Mites puncture plant cells with their mouthparts, then suck the plant fluid. The tiny areas of leaf tissue that have been killed appear as tiny dots on the the leaves. Mites often go unnoticed because they are tiny and natural controls such as weather and predators frequently keep their populations low. Severe infestations often result because these natural controls have been disrupted by pesticides and excessive dust.

Control spider mites on fruit and nut trees, azalea, fuchsia, maples and rose by regular, forceful spraying of plants with water to rinse dust and dirt off both sides of leaves. If you do have to spray to control an outbreak use insecticidal soap or a light spray oil. Sulfur is effective in reducing populations of some spider mites but this dust can disrupt beneficial predaceous mites.

Avoid using broad-spectrum pesticides which disrupt biological controls. When applied for other pests during hot weather, these can cause dramatic outbreaks of mites within just a few days even though their label may say they control mites.

Although a young or weak plant may not survive a severe spider mite infestation, it is not usually fatal to a vigorously growing tree or plant. The best defense is a good offense – periodically spray your plants with water in the morning to keep them clean and dust free.

Microclimates, Rainfall and Pests

Gardening in our microclimates might be challenging and it’s no different here in Maui. Yes, despite the balmy weather, the rainfall here limits what plants thrive. You can drive 5 minutes from an area that receives 400" of rainfall per year to another spot 10 minutes away that gets only 19" per year. Then drive another 15 minutes and you’re in a desert-like area with annual rainfall of 10" while the east side of the island, in Hana, is getting 83 inches.

Gardeners in Maui in several ways just as we do. One way is to grow the right plant in the right place. For example, at 4000 ft elevation near the volcano, 55,000 lavender plants  of 45 varieties grow happily in rocky soil. Olive trees – brought over from Santa Cruz – dot the fields. Interesting to note that the lavender plants provide a natural pesticide against the ants that invade the protea flowers. Proteas do well here. Reminded me not to miss our spectacular show of proteas  at the UC Arboretum in April and May. If you’ve never walked through this free garden it’s a treat not to be missed.

If you think all the soil here is of volcanic origin, think again. Of the 12 types of soil in the world, 7 different orders occur here.   The state of Hawaii, as a whole, has 11 types, more than any other state in the United States. By comparison, Maine has only 4 types while the Santa Cruz Mountains has a whopping 9 orders just in our little corner of the world.  Yes, folks, that’s right. No wonder gardening can be a challenge where we live.  What thrives up the road from you doesn’t always grow the same in your yard. Knowledge of soil behavior and nutrients is important where ever you garden.

Maui has a native pea, a native coffeeberry and a native huckleberry just as we do.There is even a native hydrangea although the type we are most familiar with was brought over from Japan in 1790.  Mostly, you see flowering plants introduced from other parts of the world.  Since the 1800’s, people have been bringing all types of plants to the island just like early settlers did to our area. Many of the plants that we commonly grow like the Princess flower ( tibouchina ) and strawberry guava are invasive here. Others like blue plumbago bloom in the drier areas and behave themselves. Gardeners here face the same problems as we do and strive not to dilute the native gene pool.

The rain in Maui is distributed throughout the year which is different than our Mediterranean climate. Before you get jealous, though, this allows slugs, white fly and fungus to proliferate year round. I see mealy bug under most of the plumeria leaves. This intoxicatingly fragrant tree is easy to propagate and grows everywhere on the islands. If you get at least 6 hours of hot sun per day and keep them inside or a greenhouse above 50 degrees at night they will bloom even in our area.

I’ve enjoyed my time in Maui but there’s no place like home.