There’s a hint of autumn in the air, and while tasks in the garden have slowed, it’sit’s still important to remain vigilant to keep your garden healthy. Here are a few late season pests and diseases to watch for in the garden. 

Watch for Anthracnose

This fungal infection affects squash, cucumbers, watermelons, and muskmelons, often starting as brown spots and spreading over the leaf. The look of the spots varies, depending on the attacked species. For instance, cucumbers have a yellow hallow around the spots, while when it affects watermelons, it’s more of brown, smaller spots. Overhead watering exacerbates the situation and thrives in warm, wet conditions.

There are fungicides on the market, but it is almost too late for them to do much good once you see a severe outbreak. At the end of the year, toss out the vines instead of composting them. Buying resistant seeds is one of the best ways of battling this fungus, particularly if you live in an area with warm, wet summers. 

Japanese Maple Scale Attacks in the Late Season

Lopholeucaspis japonica is a non-native scaly insect that was inadvertently introduced to the US and is causing problems in the eastern part of the country. The trunks and branches of over two dozen trees and shrubs, ranging from oaks and maples to flowering dogwood, are the most likely places to find it. The primary result of an infestation is stunting the tree’s growth and sometimes destroying entire branches. 

They have an extended life cycle (over two years) but are notoriously difficult to control. If it is spotted early, you can prune out infected branches, bag them, and dispose of them. (Or burn them. That would be my go-to.) For larger infestations, use a horticultural oil over many years to eliminate them.

Leaf-cutter Bees Late Season Activity

Leaf-cutter bees are actually good to have in the garden, but sometimes people just don’t like what they do to their plants.If you see even cuttings taken out of the edges of any number of larger leaved plants in the garden, one of the likely culprits are leaf cutter beads that are harvesting to line their nesting cavities where they lay eggs. Another option is root weevils, which we have had on lilacs in the past.

The thing with leaf-cutter bees is if you really don’t want to do anything to harm them. The damage done to the leaves is more of an aesthetic issue than anything.

Late Season Yellowjackets and Hornets

Normally, by this time of the year, we are up to our eyeballs in yellow jackets and hornets feasting upon the childbearing red raspberries. While we don’t have a major problem this season, I have talked to people in other areas who are battling these stinging insects that don’t want to share.

The problem with yellowjackets and hornets at this time of the year is the best time to deal with them is in the spring. As soon as you see them emerge, put out pheromone traps to capture and dispose of as many queens as possible. You can set out baited traps with meat or sweet items at this time of the year. The traps capture some of them, but you still must be very careful picking fruit in the garden or having a picnic anywhere.

Always Keep an Eye Open for Late Bight 

The wretched late blight, Phytophthora infestans, the pathogen responsible for the Irish Potato Famine, is something to watch out for this time of the season. Look for water-soaked lesions, often with halos, on misshapen leaves. There might also be a cottony fuzz on the underside of the leaves. It can also attack tomatoes, initially causing spots and then resulting in the death of the fruit. 

If you see something amiss, treat the tomatoes with copper or chlorothalonil products, following the label instructions on how to apply them safely. Remove the plants and dispose of them at the end of the season. Do not put them in the compost bin. Next year, be sure to purchase blight-resistant varieties to reduce your chances of contracting it again.

It’s easier in the garden at this time of the year, but it’s still possible to run into issues with pests and diseases. Always keep your eyes open and handle them immediately to reduce potential problems next year.