Got a chronic case of green thumb? Like getting your hands dirty? Adrian Higgins, garden editor for The Post's Home section, is here to help. Higgins is a firm believer in "tough plants for tough times" -- the varieties that combine good looks with stiff resistance to disease and pests. He currently rules over a garden filled with spring bulbs, daffodils, ornamental onions, perennials, asters, yarrows, hostas and day lilies. Higgins, an avid organic gardener who believes chemicals are a last resort, also tends his own herb and vegetable gardens where he grows peas, garlic, onions, lettuce, rhubarbs, radishes, carrots and more.

He was online Tuesday, July 8 to offer advice on lawns, flower beds, vegetable patches and window boxes.

A transcript follows.

Catch up on previous transcripts of The Garden Plot.

Higgins is the author of two books, "The Secret Gardens of Georgetown: Behind the Walls of Washington's Most Historic Neighborhood" and "The Washington Post Garden Book: The Ultimate Guide to Gardening in Greater Washington and the Mid-Atlantic Region."

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Wheaton, Md.: I have good peppers. Been using California Wonders for 30 years. Start them inside in early March. Harden them off outside on my sunny porch in May and plant in the garden last week of May or early June after soil is nice and warm. Plants now are over two feet tall. Looking for a bumper crop this year with all the rains of late.

Adrian Higgins: Last week we had complaints about lackluster performance of pepper plants and I invited some comments from pepper meisters: Here are a few:

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Pepper Luck: Believe it or not, my peppers -- bell, jalapeno, scotch bonnet etc, are great in pots, with a nice organic media mix...

Adrian Higgins: Keep 'em watered.

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Lexington, Va.: Last week you asked for pepper stories. This spring, I planted 8 tomato plants and 1 Anaheim chile plant at the same time, same location, in large pots with fresh potting soil, lots of sun.

The tomatoes are now lush, healthy, sprawling, brimming with small fruits and flowers.

But the pepper? Pale leaves, a few flowers, kind of sickly looking.

Adrian Higgins: OK and one not so successful.

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Lake Ridge, Va.: Would you recommend mulch on a veggie garden? If so, what kind would you suggest?

Adrian Higgins: Yes, but not shredded hardwood mulch, which I think would harbor slugs. I would use straw (not hay, which can be weedy) or pine needles.

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McLean, Va.: Good Morning, oh gardening guru,

Our gardens (flower and vegetable) survived the long weekend while we were out of town, whew. Everything grew like mad, in fact. But now we are looking to the beginning of August when it will be unattended for nearly two weeks. Are there any steps to be taken in advance to prepare the garden for an extended period on its own?

Adrian Higgins: It would be vital to do a thorough weeding between now and then, make sure the soil is well watered before you leave and to lay a thick layer of straw. Make sure that tomato plants etc are well tethered against storms. It would be good if you could get someone in to water, at least once.

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Falls Church: Submitting in advance, have to miss the chat. Spent the 4th in a beach environment with wonderful flowerbeds even in "regular" front yards, lots of perovskia (I think that is the name), lavender, coneflowers, daylilies, and ornamental grasses. I have a serious case of landscaping envy. We do have a lot of the abovementioned plants but do you have some suggestions for grasses that would do well here and maybe add that extra touch? Native preferred. Thanks!

Adrian Higgins: There are some lovely panicum varieties and molinia ones as well.

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Rockville, Maryland: Hi! I planted some Russian sage by my mailbox this spring, doing fine except for one thing: the Washington Post delivery people have tossed the paper on them at least twice. Two of them are a little lopsided now. Will they fill in? They are still young and not very woody yet. Please tell the delivery department to throw the paper on the driveway and NOT the plants!

Adrian Higgins: The only way the delivery guys can have fun at 5 in the morning is to see if they can hit your Russian sage. There's money riding on it, actually.

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Arlington, Va.: I missed last week's chat and the question about peppers. But here are my two cents. We always, without fail, have absolute bumper crops of jalapenos, far more than we can use. We've had quite poor success with bell peppers. This year I'm trying an Italian sweet pepper and so far it seems to be setting some fruit okay. Fingers crossed!

Adrian Higgins: Great, but tell us your cultivation techniques.

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Arlington, Va.: I got a pile of plant/nursery catalogs from a neighbor with great landscaping, because we are creating some flowerbeds in the fall. White Flower Farm and Burpee are some of them. But many of the plants seem pretty expensive and I feel like I could do better at Home Depot. I guess I also worry about returns and how well it works to ship plants. She did say that some plants took a year or two to settle in although now most of them are okay.

Anyway, long question short, do you or other chatters have suggestions about mail order nurseries that are good or that should be avoided? Thank you.

Also, what do you think of the Endless Summer hydrangeas?

Adrian Higgins: I think you shop on the basis of variety, quality and price. I'd rather spend $10 on a large, healthy gaura for example, than $4 on a weedy one. I like Endless Summer hydrangeas, I actually prefer the second in the series, called Blushing Bride, which has white mopheads that age to a slight rose tint.

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Ohio: I inherited a great hydrangea bush when I moved into my house a couple years ago, but I'm not sure how to prune it. Can you give me some basic guidelines?

Adrian Higgins: You should not prune it back hard, you will lose next year's flowering buds. You can and should thin out the thickest canes after the shrub becomes congested after a few years. You could do this in summer, after flowering. In April or May, after frost threat has passed, you can remove any dead stem ends.

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Montgomery Village, Md. Dr. Higgins, my beautiful Umbrella Pine has grown to a height above the second story windows. Previous owners planted the tree too close to the corner where the driveway and front walk intersect. Therefore, I've had to trim two sides of the tree so that it's now misshaped.

Is there anything I can do?

Adrian Higgins: This is a beautiful conifer and should not be pruned in a way that distorts it. It can be moved by people who know what they are doing and are prepared to hand dig it at the right time of year. Search the internet for tree movers locally.

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Pulaski, Virginia: Interesting discussion today about peppers. I planted some jalapenos to (hopefully) keep the Japanese beetles away from my roses. So far no beetles, but blackspot has just about destroyed the rose bushes. Anyway, the peppers are growing great. How big should they be when they're harvested? I've never seen them except in jars in the grocery store. Thanks!

Adrian Higgins: They will stop growing at their desired length (about four inches) and then spend another six weeks going from green to red. You can harvest them at either stage.

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Rockville, Maryland: Thanks for the advice on my slow tomatoes. They have lots of blossoms now. I used some old fabric hose to tie them up and they seem fine now. Waiting for fruit, of course.

Adrian Higgins: Great.

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Growing basil and mi, nt: As a first time gardener, I'm happy to see that my tomato plants are doing great. We used some in a caprese salad this weekend along with the basil that I'm growing in a container.

My herb container didn't do as well as I hoped. I planted rosemary, basil, mint and thyme in a round container. The basil is doing great, but that's the only thing that grew. Talking to my mother-in-law this weekend, she said that you shouldn't grow basil and mint together. Is this true?

Adrian Higgins: Basil is an annual that likes even moisture but not wet soil, mint is a perennial that loves water, so they're not ideal companions, no.

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Green Worms on Red Cabbage: While it might make for a nice Christmas card, I'd prefer my red cabbage to be monotone.

I recently noticed worms (caterpillars?) about 1" long or so (not inchworms) on each of my cabbage heads. What can I do (organically) to prevent/deter pests such as these from making a meal from my garden before I have a chance to harvest it myself?

Adrian Higgins: Undoubtedly the larvae of the cabbage white butterfly, you can pick them off, difficult given the leaf structure of cabbage, or you can spray with Bt (or both). Another option would be to cover the cabbages with a floating row cover, but only after you have got all the current pests first.

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Arlington re: peppers: Our jalapenos tend to do well in a mostly sunny bed (neighbor's tree, can't help a little shade late in the day) that's mainly native soil, amended somewhat with composted manure and the like over the years because we've grown tomatoes there, but we have added nothing special for the peppers. We water with the tomatoes, rarely fertilize. Pick them often.

Our Italian peppers are in a sunny raised bed with garden soil, preexisting dirt, and shredded leaf compost, our new experiment this year. So far, so good.

Adrian Higgins: Another pepper tip.

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Pulaski, Virginia: I like Endless Summer hydrangeas too and planted two Blushing Brides in April, 2007. But for some reason they aren't leafing out this year although the stems are still green under the bark when I scrape it off. I kept them watered during last year's drought so I can't understand what's wrong with them. Do you have any ideas?

Adrian Higgins: I don't know how they could be alive if they haven't foliated this year, unless deer are eating the burgeoning growth. At the very least, I would move them to a site away from foragers and with well amended soil.

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Silver Spring, Md.: Good late morning,

What does it mean when there is a patch of yellow slime on top of mulch? Is that mold? Is there anything that I can do to prevent this?

Thanks very much.

Adrian Higgins: This is slime mold, quite harmless, if revolting. I suppose you could put it in a bag if it offends you, but once the mold dries, the spores are ripe, and moving it at that point will only release them into the air.

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Arlington, Va.: I have a St. John's Wort that has not been pruned in years. The base is now quite woody. Could I do a hard prune this fall or would it harm the plant? Thanks. I appreciate the chat!

Adrian Higgins: You could either hard prune it now, and allow new growth this season, or wait until November or December.

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Post delivery : I feel for the chatter whose newspaper keeps ending up in the flowers. This happened to us for literally years - coneflower decapitation was the objective, we figured - even though our driveway seemed to me a much easier target. We'd ding the driver on the tip and write "please don't hit the flowerbeds" on the bill. Maybe that was counterproductive. I figure we just have a new driver now because it doesn't happen any more.

I suspect this is a common complaint.

Adrian Higgins: Perhaps.

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Climbing Roses in Centreville, Va.: Our climbing roses (White Eden) bloomed like mad in the April/May timeframe. Once they peaked, I deadheaded the spent blossoms. The canes are reaching for the stars (a few of them at 10'+), but there's no more growth in terms of new buds. They face the east in front of the house and get a full dose of sun (8 hours) and I feed them regularly w/Bayer rose food.

How do I get them to set more buds... or do I wait until next year?

Adrian Higgins: Few climbers are really good at reblooming. I don't know how remontant this rose is, but any subsequent blooming is going to be merely an echo of last spring, and won't occur until late August. Don't go mad with the fertilizer.

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Arlington, Va.: I don't like the idea of using wood mulch on flower beds or trees right next to the house. What might be good to use instead?

Adrian Higgins: Pea gravel is attractive and effective.

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Virginia: Hi Mr. Higgins,

Do you look at landscaping and think to yourself, "that is going to look so dated in a few years?" It seems like just about everyone is planting the same things lately in my neighborhood and I'm curious if you see garden trends for 2008 that won't stand the test of time, i.e. the avocado appliance of the gardening world.

Adrian Higgins: Yes, you can tell the age of neighborhoods by the tree plantings, in the 70s and 80s, we became Bradford pear land, which has come back to haunt us. I think the Natchez crape myrtle is a wonderful ornamental tree, but grossly overplanted by folks who don't realize how big it will get (30 feet)or how dense its shade.

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Front Royal, Va.: On the latest, greatest groundhog prevention program. Too many ground hog holes on our property to pee in each one. Any ideas on how to protect squash plants (the only veg they seem to be eating... besides morning glory vines)?

Adrian Higgins: If they are just going for the squash, you could try spraying with a repellent, and also training the vines up a trellis so they won't get to the flowers or fruit.

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Hydrangeas: The questions about hydrangeas reminded me of a question. I would like a purple-blue hydrangea, not the Nikko blue one that reminds me of a grandmother's garden (sorry, everyone has an opinion :). And preferably a lacecap. Do you have any suggestions for nice ones?

Adrian Higgins: I like Blue Bird a lot, and Tokyo Delight is a good choice.

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Arlington, Va.: Hi Adrian, love your chat. I'm growing tomatoes in containers on my south facing balcony, which gets plenty of direct sunlight. This past week, I noticed a few of the tomatoes have blossom-end rot. Is there anything I can do to save the other tomatoes? Or is it because they are being grown in containers?

Thank you!

Adrian Higgins: They are prone to it in containers, because the disease is caused by calcium deficiency and uneven watering. Remove the affected fruit, scratch in some bone meal or limestone, and water the plants frequently.

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Arlington: I just harvested my first crop of garlic. What is a good crop to plant in the same area? Last year I grew sugar snap peas and beans? Thanks.

Adrian Higgins: Both of those would be good choices. It's a little early to sow fall crops. I just sowed some carrots for a late harvest. Beets would be ok too.

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Capitol Hill, D.C.: Hi Adrian. I'm a gardening newbie struggling to tread water with my little rowhouse front garden. Our garden, like many others in our neighborhood, has a problem with some kind of really fast-growing vine that coils its long tendrils around anything in its path (trees, plants, railings). The leaves are spade-shaped. Is that enough description to identify it? And what can we do about it other than keep looking for the shoots that appear out of nowhere overnight. Thanks!

Adrian Higgins: This is bindweed, which can be controlled, but you have to keep pulling it.

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Woodbridge, Va.: Good morning. We have a sycamore tree about 25 feet tall that is generally pretty healthy. Except for one thing: each summer (this year and last), the leaves start to shrivel up, turn yellow and fall. New leaves grow back before the end of summer, so we don't tend to worry too much. The tree gets good watering, especially with all the rain this year. Is this a problem we should be concerned about? Thanks!

Adrian Higgins: Sycamores suffer from anthracnose disease, especially in wet years like this one. There's not much you can do about it.

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New York, New York: What are some annuals that I can use in my window boxes that will withstand the heat and humidity of summer? Some things, like petunias, melt when the humidity spikes, and others can't take even a bit if drought if I don't water every morning. I figure that if you are gardening in the swamp of DC you must have dealt with this.

Adrian Higgins: Lantana loves the heat and humidity.

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Silver Spring, Md.: Hi Adrian,

We have a sunny area along our driveway that has been mulched but I know the weeds will return unless I plant it. It's probably 4x20ft or so, full sun. I'm thinking some grasses. Small trees won't work there but any other suggestions for a full sun area? Thanks ...

Adrian Higgins: You could create a wonderful screen of different grasses, including miscanthus, calamagrostis and panicums.

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Washington, D.C.: Is there anything I can do to make my blueberries sweeter? They are tart even when plump and ripe.

Adrian Higgins: Blueberries look ripe for two weeks before they actually are,also they don't all ripen at the same time. If they twist off easily, they are ripe, if there is resistance, leave them for later.

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Venice, Italy: Hi Adrian,

I have a lemon tree in a pot in my back yard that has been covered with ants this year. I think they've been laying eggs on the little lemons as well. Will the ants harm the tree? Are they responsible for some of the little lemons falling off? And what can I do to keep them away that will still allow me to eat the lemons?

Thanks!

Adrian Higgins: This is my first question from Italia, so I have to answer it. Ants in themselves are not harmful, but their presence suggests that they are farming pests that are harmful, either scale insects or mealybugs. Both can live in the soil, so you can actually dunk the pot in a tub of water and drown them. Keep it submerged for a couple of hours. Alternatively, you can cradle the tub with rope and lower it into one of the canals. Watch out for passing gondolas.

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Arlington, Va.: I planted white daisies last fall on both sides of my front yard. This year, one side has done very well, but the other side, the plants are dying. The plants didn't grow to full height and are only about eight inches tall. On each plant, individual stalks are withered and are absolutely dead. Other stalks on the same plant are flourishing. This has happened on multiple plants. Any thoughts? Did I just not give them enough water? Is the concrete retaining wall affecting them? I'm bewildered.

Adrian Higgins: I suspect the soil and drainage conditions are different, I would lift the ailing plant and see if you have root rot from excessive moisture.

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Front Royal groundhogs: I have a trellis, but the squash plants, alas, were munched before it made it up that high. We still have a few leaves remaining, so I haven't given up. I'd heard that it is a bad idea to spray things on veggies that we eat... is there a repellant that you would recommend that wouldn't end up in the veg and hurt us?

Adrian Higgins: There are organic based repellents (two spellings both correct) that include garlic and eggs.

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Tomatoes -- early blight?: My Brandywine plant appears to have "early blight" -- what should I do about it?

Adrian Higgins: Remove the affected leaves and add a generous layer of organic mulch, again, straw would be a good choice.

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Chantilly, Va.: I've got a row of azaleas on the side of my house that I fear are too close to the foundation. They were planted by the previous owner and are about a foot or so from the house.

I'd like to move them so that they're at least two feet (if not more) from the house, but am not sure when to do so. They're about 2.5' tall and about just as wide.

When would be the optimal time to do this, how far should they be and what should I do to have a better chance at success?

Adrian Higgins: Azaleas move easily, but do it in September or October.

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Lancaster, Pa.: Hi, Adrian:

I'm having a horrible -- and on-going -- time with one of my daylily beds. The plants come up just fine and then about the third week in June, the leaves turn yellow and then they die. The bed looks terrible -- this year is the worst. (This has happened three years in a row.) Does whatever is affecting them live from year to year (in the ground/on the plants)? What should I do? I always thought daylilies were indestructible. I would hate to destroy the plants -- they were transplanted from a really old property in Richmond that my sister once owned and they have sentimental value. Any suggestions would be greatly appreciated.

Adrian Higgins: This may be daylily rust disease, or a virus. If it's the former, remove all the leaves now, spray with a fungicide labeled for daylily rust. Good sanitation is a must, so bag all the leaves. If it's a virus, there's not much that can be done, and the daylilies should be replaced with something else. Try the rust approach first and see if that works. It may take a year to find out.

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Washington, D.C.: Help! I garden in flower boxes on my balcony and I am being inundated with spiders that look like extras from the Lord of the Rings movies (which means BIG). I wipe the cobwebs off the flowers, boxes, and chairs every night when I water, but they're back almost the next day. I know that spiders are helpful insects, but this is getting out of hand. Can you suggest how I can control the critters? Thanks!

Adrian Higgins: YOu could always kill some of them, I suppose. I tend to transport unwanted spiders to other parts of the garden. They really are helpful in reducing pests like mosquitoes.

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Houston, Tex.: I need to find something for my yard, something that grows well in this hot, humid Houston weather. And doesn't need a lot of light, for much of my yard is heavily shaded. Thoughts?

Adrian Higgins: If you can bear annuals, you could do a lot with coleus and caladiums.

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Gaithersburg, Md.: The Sunshine Blue blueberry bush that I've carefully nurtured for three seasons put out a bumper crop of big, green berries this spring. I covered the bush with bird netting, down to the ground, to keep the birds from getting to the berries. But the berries are disappearing just before they're ripe enough to eat. The branches and leaves are intact; only the berries are missing. If it's not birds or deer (or people), who is taking my berries, and what can I do about it?

Adrian Higgins: I'm pretty sure that you have birds infiltrating the net, perhaps a wren or a catbird. Make sure that it is fully secured.

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Columbine: My neighbor harvested a bunch of columbine seeds from her plants a few weeks ago, and gave me quite a few. I have no idea what to do with them. Do I plant them in the spring or the fall before frost? Or now? Or in a pot? I know they like some shade.

Signed, Clueless

Adrian Higgins: Sow them in 4 inch pots, which should be kept outside, in the shade, in a good potting mix that includes peat moss and perlite. Don't let them dry out or get excessively wet. They may not germinate until next spring, so be patient.

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Martinsburg, W.V.: I'm interested in planting Double Knock-Out Roses in front of my house, which would face east. When would be the best time for planting and would east work well?

Adrian Higgins: If it's from a pot, you could plant it now, on a cloudy day. Enrich the soil and water the roots, but avoid overhead irrigation to limit black spot. We're out of time, I'm afraid, but check out Thursday's Home section for more gardening coverage and wayward deliveries.

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