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Your garlic, shallot and onion plants might need protecting from the leek moth

Close up of green, tall leek plants growing in a row of brown garden soil.
YuriyS/Getty Images/iStockphoto
Leeks, shallots, garlic and onions can fall prey to a recent newcomer to our region - the leek month. Learn how to keep your alliums safe and healthy.

Your garden is beginning to show off its finest greenery, as radishes and carrot greens grow taller and tomato plants become sturdier and begin to flower.

You've got a good handle on how to keep pests and wildlife out of your raised beds and what methods to use to keep insects at bay.

One family of plants - the allium group - has remained relatively pest-free until recently. And now your garlic, onions, shallots and leeks might need you as the first defense against the leek moth.

Migrating from Canada a couple of decades ago, the leek moth has made its way to upstate New York, nearly all of Vermont and northern New Hampshire now, too.

If you've planted garlic, for instance, the bulbs underground are just beginning to send up their whorl of leaves. That's where the leek moth lays its egg.

From the tiny moth egg, a small green caterpillar hatches and begins to eat the garlic leaves. So if you have leek moths, this is where you will begin to notice damage on your garlic and garlic scapes.

Right about now, garlic plants are up and growing. They still need more time to grow before harvesting.

You might not think leaf damage from the leek moth caterpillar will affect your garlic bulbs. But in that time between now and harvesting them, the leek moth caterpillar can burrow down and cause damage to the garlic bulbs as well.

So, in this interim growing time before harvesting your garlic bulbs, try spraying an organic pesticide like Bacillus thuringiensisor BT on the plants.

This pesticide, even though its organic, kills all caterpillars, including the swallowtail butterfly caterpillar. Do take care that you're not spraying indiscriminately.

To eradicate the leek moth caterpillar on your garlic plants, just spray the BT directly into the center of the leaves. The best time to spray is in the evening with calm to no wind.

If you've added onions and leeks to your gardens and raised beds, they need to grow a lot longer before harvesting.

In the case of these allium plants, combatting the leek moth becomes a bit more complicated.

The leek moth hatches two or three generations each year. That would require a lot of spraying to keep up.

Instead, try to prevent the leek moth from getting into your garden in the first place.

You can do this with micro mesh. Micro mesh is similar to a floating row cover. It's made out of a window screen material that's really tough and flexible. Sun and rain will still get through but not not the leek moth.

First, push some metal hoops into the soil then drape the micro mesh over that. Your onions and leeks will have a better shot of growing to maturity underneath that.

Q: I did notice fewer conventional tulips this year compared to last year when they were freshly planted. Are conventional tulips annual or perennial? And is there anything we can do to make them last longer in the garden? - Emily, in Montpelier

A: Conventional hybrid tulips that we plant are indeed perennials. They do come back year after year, but they have been so hybridized that they don't do very well in our climate and they are not made for growing in gardens.

Read up on tulip varieties from All Things Gardening: Double or single, fringed or twisted, the species tulip comes back year after year

These varieties are highly hybridized and are intended for the cut flower industry in Holland more than growing in gardens.

The cycle is pretty similar: the first year you plant the tulip bulbs, they look great! The second year, maybe you get a few flowers, by the third year, you're just getting foliage.

You don't have to give up on these traditional hybridized tulips, though! After they're done blooming around this time of year and the foliage has yellowed, dig them up.

Take a look at the individual tulip bulbs. If you see little baby "bulblets" all the way around them, knock or peel those off from the mother bulb. You can then replant the mother bulb and add some bulb-boosting fertilizer.

Or you could dig up the bulbs and dry them and then plant them again in the fall when we normally plant tulip bulbs.

These are techniques for giving hybridized tulips new life and hopefully get them to flower again.

Andspecies tulips don't really have this issue. They tend to come back year after year, regardless of whether they've been hybridized or not.

All Things Gardening is powered by you, the listener! Send your gardening questions and conundrums and Charlie may answer them in upcoming episodes. You can also leave a voicemail with your gardening question by calling VPR at (802) 655-9451.

Hear All Things Gardening during Weekend Edition Sunday with VPR host Mary Engisch, Sunday mornings at 9:35.

Have questions, comments or tips?Send us a messageor get in touch by tweeting us @vprnet.

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Mary Williams Engisch is a local host on All Things Considered.
Charlie Nardozzi is a nationally recognized garden writer, radio and TV show host, consultant, and speaker. Charlie is the host of All Things Gardening on Sunday mornings at 9:35 during Weekend Edition on Vermont Public. Charlie is a guest on Vermont Public's Vermont Edition during the growing season. He also offers garden tips on local television and is a frequent guest on national programs.