YOU HAVE A LOT OF QUESTIONS, I know, and some of your most-asked recent ones include when to harvest garlic; how to get better seed germination in hot, dry summer soil; how to combat squash bugs, and more. On the latest edition of my weekly public-radio show and podcast, I asked the originator of the Urgent Garden Question, my sister Marion Roach Smith, to come help–to be my Vanna White, so to speak (though this particular Vanna is a redhead).  We tried to provide the answers:

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YOUR QUESTIONS were the topic of the latest edition of my weekly public-radio program with guest Marion Roach Smith. Listen anywhere, anytime: Locally, in my Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) region, “A Way to Garden” airs on Robin Hood Radio’s three stations on Monday at 8:30 AM Eastern, with a rerun at 8:30 Saturdays. It is available free on iTunes, the Stitcher app, or streaming from RobinHoodRadio.com or via its RSS feed. The July 1, 2013 show can be streamed here now. Robin Hood is the smallest NPR station in the nation; our garden show marked the start of its fourth year in March, and is syndicated via PRX.

the q&a of your top garden questions

Q: Everybody’s impatient–and wants to know when to harvest their garlic. How do you know when garlic is ready to pull, since you can’t see the bulb below the ground, of course?

A. Garlic dries from the bottom up, so you’ll see leaves go brown gradually starting near the soil level. When four or five leaves (or five or six, some experts say—maybe we should compromise on five?) are still green, experiment by lifting a couple of heads. You don’t want to let them go all brown in the ground, the way you can with onions. Here’s the whole story on when and how to harvest garlic.

Q: Ellen wrote in to ask: I didn’t feed my shrubs and trees in spring, because the weather was just so crazy – I never got to it. Can I feed them now?

A. No food for those woody plants, I’m afraid, at least if you are (as I am) in an area where there’s a real winter sometime in your garden’s future. Encouraging trees and shrubs to put on fresh, tender new growth now, when they should be working on hardening off the growth they pushed in spring, would leave the newest parts vulnerable to dieback when frost does come. Late winter or earliest spring is generally the best time for fertilizing them.

Q. Readers have had lots of questions lately about poor seed germination, as soil generally heats up and gets dry with summer taking hold. How can they get vegetable seeds to germinate as they try to sow crops for fall harvest? Lots of people are having trouble with carrots, in particular.

A. The soil can be hot and inhospitable in summer for many things here at my garden, too. And yes, carrots are tricky, but other things may also just sulk and not germinate or germinate erratically if the soil crusts over, or if the seeds dry out when they are all vulnerable and trying to sprout.

Carrots are really finicky about crusting of soil–which can occur especially when it has been over-worked (tilled mechanically, for instance) or from weather extremes.

John Navazio of the Organic Seed Alliance, a longtime carrot breeder, says carrots want “unchecked growth”–meaning no interruptions or impediments along the way. Not from a stone in the seedbed, not from lack of water, not from crusty soil…and I think that’s a good goal with all seeds, if you can provide it.

John recommends this trick to “mulching” the seedbed after sowing and watering, to prevent crusting: “Sprinkle a very light layer of grass clippings on top of the row to keep things moist.

The tip John likes best for breaking through crust is to employ some living helpers: “Sow radish or even better turnip seed among the carrots,” he says. “Both germinate extra-fast, and help break through any possible crust, and also mark the row, since they sprout before the carrots.” Pick the tiny plants and eat the baby leaves in salad, he recommends. How to grow carrots, in detail.

As I said before, I’ve had erratic germination for various reasons of extreme weather this year, including stretches of hot, dry soil. What I do a day or two or three before I direct-sow anything in a dry, hot spell:

Cultivate the seedbed lightly, water deeply, and put up a stretch of shade cloth of some kind, on hoops, to cool down the soil.

When I sow, I cultivate lightly again with my hand fork, very lightly moisten the area again, plant the seeds and cover and moisten again. I leave the shade cloth up if it’s forecast to stay hot.

I’ll do this with my fall peas, for instance–sown here in early July. I cool down the row a few days ahead with repeat waterings and shade, and leave the emerging peas shaded. Spinach and lettuce like this treatment, too.

Q: Pests seem to be another popular topic lately – especially insect pests. For instance, what should people do about squash bugs?

A. The key to managing squash bugs is to not let them build up. This means if you’re seeing them now, you must do what you can at once, plus do a strict cleanup in the fall to reduce overwintering of unmated adults and improve your chances for next year.

They also require prompt attention in the spring, when young plants are especially susceptible and insect populations are rising. I check the undersides of leaves daily for egg masses or nymphs (recently hatched bugs). You can see what each stage—egg, various nymphs, adult—looks like on the University of Minnesota Extension site here. I catch adults in the early part of the day near the base of the plants or under leaves, and you can lure them to hide under boards or shingles at night much like you would slugs by day, but they move much faster once fully active. “Empty” your traps first thing daily.

Growing pest-resistant varieties is recommended in areas where the squash bug is a problem, and it really improves results. Besides ‘Butternut,’ which is a winner for me, the University of Arkansas suggests ‘Royal Acorn,’ ‘Sweet Cheese,’ ‘Green-striped Cushaw,’ ‘Pink Banana,’ and ‘Black Zucchini.’

And then there is the tactic of succession sowing—one of the best defenses a gardener has against wholesale loss of any crop, really. Plan to have multiple sowings coming along—not all your cucurbits at the same stage of development at once, potentially coinciding with the worst invasion.

My entire story on squash bugs is here.

meet my sister the writing teacher

MARION ROACH SMITH teaches memoir writing, in classes, in virtual consultations, and online. She’s the author of “The Memoir Project” (Amazon affiliate link), an easy-to-follow handbook that can get anybody writing their story.

Visit her at her blog, where there are book giveaways of new memoirs, and how-to instruction to get past what has you stuck on what Marion calls, “writing what you know.”