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How Do I Manage Codling Moths on Fruit Trees?

 

“I have a Liberty apple tree and a peach tree within 20 ft of each other and every year fruit tries to grow but what I believe is the coddling moth destroy it all. Do you have an effective solution?  Sprays have not helped.” Question from Ilene of West Greenwich, Rhode Island

Answer: It is likely that you are dealing with European apple codling moths (Cydia pomonella) and Asian peach moths (Grapholita molesta). Both exist in Rhode Island, look similar, and cause comparable damage, but one prefers peaches, and the other chooses apples. Here are three suggestions for overcoming these pests in your home orchard.

Know Your Pests

European apple codling moths (Cydia pomonella) are 1 cm, greyish brown, and have curved antennae. Their wings fold into a tent-like shape.

The codling moth is small and mottled with greyish-brown. Its wings fold in a tent-like manner, and it reaches about 1 cm in length. You will see them most often in the orchard from late May to mid-July. (Click here to learn more.) The Asian peach moth is smaller, mottled, gray, and measures about 1/4 inch (5 mm). The wings have mottled light and dark banding and also fold in a tent-like manner.  The first adults of the season appear from mid- to late-May. Subsequent generations appear from June through to mid-July. (Click here for more information.)

Keep Orchards and Trees Clean

In fall, remove all spoiled, fallen fruits that may harbor moths, bag them, and dispose of them away from your orchard. Look for the codling moth’s brownish moth pupae in winter, which can be found in protected spots near where apples are stored and in tree bark. The moths emerge in mid-spring ready to attack fruits.

I also recommend cleaning and disposing of all fallen fruit-tree leaves to reduce the prevalence of any potential fungal diseases that overwinter on dried foliage.

Time Your Spraying

Time your spraying with precision to stop these pests. A good time to first spray trees is in spring a week after they have dropped all of their petals. This should help tackle the first wave of both codling moths and Asian peach moths. The second time to spray is when the fruits are developing. Codling moths lay single white eggs on the fruits and leaves. These can be manually removed from fruits. Never spray trees when they are in flower. Otherwise, you will be killing all the essential pollinators, while not harming the moths.

I recommend two sprays for these pests: Codling moth virus and horticultural oil are approved for organic gardening, and will stop your apple moths, but frequent applications are needed. Organic insecticides with the beneficial bacterium Spinosad work well against both moths, but these sprays can only be applied several times in a season, so read the product instructions.

Use Sticky Traps

There are pheromone traps designed to just trap and kill these two pests. Set them up by mid to late May just before the first round of moths start flying. These should really help lower your populations and save you some fruit.

I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Growing Dwarf Apple Trees

Dwarf apple trees can fit into practically any sunny, small-space garden.

Walking out on your deck, balcony, or patio and being able to pick fresh apples off your own tree may be a dream to most gardeners.  In the world of today, we often have small lots, which means less available space for a standard-sized fruit tree.  Even if we did have space, there may be other competing factors to prevent an apple tree from flourishing, such as shade from a neighboring house or a mature tree casting shade and expansive roots, competing for sun, water, and nutrients. For many urban and small-space gardeners, dwarf apple trees (Malus domestica) is the solution, and fall is the best time to plant them.

Even with limited space, dwarf fruit trees can grow and thrive, if provided good ground. These small trees will even grow well in large containers, so they can be grown on a sturdy balcony or small patio if given adequate sunlight and good care.

What Makes Dwarf Apples Dwarf?

Garden centers sell our favorite apple varieties, like ‘Honeycrisp’, ‘Fuji’, or ‘Red Delicious’, as very very dwarf (5-7′ tall), dwarf (6-10 feet tall), or semi-dwarf (8-12 feet tall). The fact is, any apple variety can be in compact form if it is grafted onto dwarfing rootstock. So, what is grafting and how does it work?

A row of dwarf ‘Red Delicious’ apple trees.

Every commercial apple you buy is actually two apple varieties grafted or joined together; one variety is the main tree (scion) while the second variety is the rootstock. The scion of a dwarf tree is grafted onto dwarfing rootstock, so it’s the rootstock that controls tree size, among other factors such as disease resistance, hardiness, and vigor. (Learn all about the grafting process here.)

It is unfortunate that plant labels on apple trees don’t tell the whole story. It is as important to know what the rootstock variety is and the scion variety because the rootstock determines how a tree will grow. There are many different apple rootstocks. For example, G65 is one of the most dwarfing varieties, producing trees reaching about 4-7 feet.  The next size up would be a rootstock called M9, producing trees reaching about 6-10 feet.  (Learn all about dwarfing rootstocks here.)

The Best Dwarf Apple Trees

A semi-dwarf apple tree.

For apple trees in general, all need to be cross-pollinated, which requires two trees to be planted in close proximity to each other.  Apples can be early-, early-mid-,  mid-, mid-late-, or late-blooming, so you need to choose at least two trees that bloom at the same time for cross-pollination. Apples are primarily honeybee pollinated, so it also helps to plant other garden flowers and shrubs for honeybees, to make sure there are lots of pollinators in your garden to help your apples. (To learn more about flower gardening for bees click here. To learn more about trees for bees click here.)

‘Golden Delicious’ is a great eating apple and popular pollenizing tree for other mid-season varieties, like ‘Jonagold’ or ‘Gala’. Likewise, the mid-late-blooming ‘Honeycrisp’ will pollenize other mid-late-bloomers, like ‘Granny Smith’. Just choose the apples you like best, whether they be for fresh eating, cooking, or cider, and be sure their bloom is coordinated for best production. (For a full list of apple pollenizers, click here.)

Growing Dwarf Apple Trees

Dwarf apple trees are ideal for growing in large containers that are at least 10-15 gallons.  If planting in a container, fill the pot with one part Black Gold Natural & Organic Potting Mix mixed with one part Black Gold Garden Soil. If planting in the ground, good drainage and good soil quality are essential. Amend the soil with Black Gold Garden Soil before planting to increase organic matter.  A yearly top dressing of Black Gold Garden Compost Blend is ideal for trees in containers or in the ground.  When placing your trees, remember that the critical factor is the sun; these trees should have daylong direct sunlight.

Espaliered fruit trees are great for training against walls or fences. (Image by Jessie Keith)

Gardeners with very little space should look for apples that are espaliered for training against a fence, trellis, or wall.  Espaliered trees require harsher pruning if they are to be maintained in their attractive architectural form, but they are space saving.

Yearly pruning in late winter will also help standard dwarf apples. Remove crossing or unwieldy stems as well as unwanted water sprouts that may arise from the rootstock. Another important step to winter care is spraying trees with dormant oil spray to control common pests, like whitefly, mealybugs, mites, and aphids. Spray before your trees have leafed out and when temperatures are below 40ºF.

Check out your local garden center in fall because if they have dwarf fruit trees, it is likely they will be on sale.  If they are not available now, spring would offer a better selection.  You might be pleasantly surprised at how easy it is to have fresh apples to pick from your own trees.