The Garden Plot

Adrian Higgins
Washington Post Garden Editor
Tuesday, July 18, 2006; 11:00 AM

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.

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."


Fairfax, Va: Adrian,

Is there any natural fertilizer I can use on my grass ? I don't mean the commercial mixes, but something that helps without all of the extra chemicals.

Adrian Higgins: Depends how organic you want to go. One thing you might consider is buying or making compost tea, a process too involved to discuss here but easily attainble by Googling, I would imagine. Some independent garden centers sell the stuff (I think American Plant Food. You can spray this on the lawn and this will build the microbial life quickly.


Pittsburgh, Pa: Adrian,

My lawn is entirely zoysia grass. Is there anything that I should use on it, besides the commercial mixes ? I've heard that zoysia likes to be fertilized every 4 weeks or so.

The yard is nice and green and I'd like to keep it that way.

Adrian Higgins: Zoysia likes to be fertilized in the summer, when it is growing (unlike cool season grasses, which should not be fed now). You need a pound of slow release nitrogen fertilizer per 1,000 square feet.


Chevy Chase, Md: Hi - thanks for all your great help in the past. I have a very un-glamorous question today!

Due to an apparent language barrier with a crew we hired to do some weeding, we now have a 6x20 foot slope with no vegetation of any kind. It is probably an 80 degree slope and we are very worried about erosion and mudslides next time it rains. Can you recommend anything we could plant that will take quickly with enough of a root system to avoid erosion? Are there any stop-gap measures in the meantime? We've been told covering it with stones, a mesh or landscaping fabric, or even sandbags might help. We're really in a bind here... Thanks so much for any thoughts!

Adrian Higgins: I would cover the hill with burlap, pegged with landscape staples, and cover that with shredded hardwood mulch. Then decide how you want to plant it. Some dry loving ground cover would be in order.


Denver, Colo: Adrian,

I cut my asters back once in May, and now they're getting tall and bushy again. Should I cut them back again ?

Adrian Higgins: I wouldn't, I think they might bloom too late. I recommend just one cutting of asters in late May or early June.


Adams-Morgan, Washington, DC: Any idea why my sweet basil is tasting bitter? I am growing it in a large pot on my apartment roof top.


Adrian Higgins: I think it is going to seed or about to go to seed. I would try and plant some fresh or cut it back hard. Make sure it receives even moisture.


Plants that Like Bugs in VA: Adrian,

I've got five bug-eating plants - oh, I love 'em! But I've read mixed information on the amount of water, humidity and type of soil they need. Right now, three are in a basin of distilled water, two are in individual pots of moss, water with distilled water. They're all outside. Do they need to be in a bell jar or need different soil? Thanks.

Adrian Higgins: As a rule, carnivorous plants such as sarracenias need poor, acidic soil, a blend of sand and peat moss is good, and constant moisture. They should be watered with rainwater, not tap water.


Silver Spring, Md- Does it really work: Adrian, I have lots of kids and pets and lots of weeds have refrained from weed killer.I have hand pulled many of the larger weeds especially after the rain. The kids help but the clover is spreading. I am planning on reseeding in the fall but does a high acidic vinegar really work?

Adrian Higgins: I think it would but it is far more acidic than table vinegar. Don't splash it in your eyes.


Clarksville, Md: My wife and I have a small debate going. We have a vegetable garden (10 x 10) and 3 acres of yard. How close to the garden should the Japanese Beetle trap be ?

Adrian Higgins: 50 miles. Not close anyway.


Ashland, Va: Mr Higgins. After years of Apartment living I've purchased my first home, and am now overcome with lawnophobia. The yard is overall in good shape with a few thin spots here and there, and a few bare spots (mostly were the sun bakes all day). All in all though not to bad. What would you suggest (re-seeding, lawn fert., etc) I do to have the best yard on the block, and at what time of the year should this be done.

Adrian Higgins: Your interest is peaking at the right time. Late summer is ideal for lawn renovation, and I find that by seeding a little earlier than recommended, you get a great stand of cool season turf before the leaves fall. I would get a soil test now to see what nutrients are lacking, and to get the pH right. Then in late August or early September, fill in low spots, top dress the entire lawn with screened compost and get it core aerated, and then seed.


When is corn ready to pick?: Hello from Oklahoma City where the high today is predicted to be 104...

Adrian: How do you know when it's time to pick an ear of corn? My husband and I have a crop growing in an Earth Box, and as of today we have 7 or 8 white silky tops visable -- looking good so far. But what is the peak of ripeness indicator? This is our first effort. Thank you for taking my question. Take care....

Adrian Higgins: You want to wait until the silks are about half to two thirds brown. Then the kernels should be ripe. Pick one at half brown stage and see if it's OK, then try one with the silk a little browner, and compare.


Wheaton, Md: Good morning.

My tomatoes are not doing very well this year, and I was wondering if you had any advice.

I got my plants in about the beginning of May - I bought 7 plants from HD, and they started out looking pretty good. However, after all of the rains, the stalks are yellowish, and they haven't gotten very big. I'd say the tallest plant is about 2 feet at this point.

We have harvested several tomatoes already, and they have been tasty. However the plants don't look very healthy.

The plants are in full afternoon sun, and are in the same location where I have been growing tomatoes for several years. So I know the location is a good one.

Any advice on how to salvage the rest of the summer for these plants?


Adrian Higgins: First of all, tomatoes that went in a little late still have a lot of growing to do, which they will do in the next month. Second, blight on the leaves will set them back, and you need to remove the yellowed leaves and discard them and take care not to spread the blight to healthy foliage. It is conceivable that your tomatoes may be suffering from waterlogging. If you are convinced that isn't the problem, however, I would give them a feeding. I use a little superphosphate fertilizer once and then a weekly feed of diluted seaweed fertilizer.


Vienna, Va: Adrian,

When and where is your weekly talk show ?

Adrian Higgins: I'm on Washington Post radio from 7 to 8 a.m. on Saturdays, on the David Burd show. I sometimes appear on Hillary Howard's show on Wednesdays at 11:30 a.m. I know David loves people to call in with gardening questions, as do I. 202 465-3081.


Springfield Va: Are there any holly plants / evergreens / laurels that can tolerate full shade? I'd like a screening device (around 6' high) but am having a hard time finding one that will work under the canopy of american beech and tulip poplars.

Thanks for your help!

Adrian Higgins: Cherry laurels will take shade, as will aucubas, yews, camellias and various hollies. Do check though to see if you have dry shade, in which case you will need to make sure that the understory plantings get enough moisture.


Batimore Md: Someone gave me a small hydranga bush last year. I planted it in a place that gets a lot of shade, I almost killed it be forgetting to water it. However, it has come back this year, but all I have is leaves, no blooms. Should the plant be moved or perhaps it may bloom next year?

Adrian Higgins: It will bloom better in light shade than in full shade. Don't prune it.


Rockville, Md: Thank you so much for these chats, they are really valuable.

I'll be going away for three weeks. I've purchased a timer and soaker hoses for my recently installed gardens (everything from roses to rosemary, tomatoes to a peach tree). Can you recommend for how long and how often I should set the timer? For example, once per week for 30 minutes? Something more frequent?

Also, can deciduous azaleas get blackspot because mine have something that looks like that? Any advice?

Thank you so very much.

Adrian Higgins: Three weeks is a long time to be away at this time of year. Bah humbug. It's tough to get each plant's differing needs met automatically. Shrubs need less than lawn, herbs less than shrubs. Containers need watering every day or two. For a plant border, I would say 30 minutes twice a week, perhaps.


Washington DC: What could be the cause of the leaves of my Azalea bushes turning brown? Is there anything I can do to help them.

Could they be getting too much sun? What is the ideal amount of sun they should get?

Many thanks.

Adrian Higgins: Possibly leaf spot diseases promoted by all the rain we have had. I wouldn't worry about it.


Bowie, Md: I've got a few tomato plants where the tomatoes are both green and red. When's a good time to pick a red tomato?

Adrian Higgins: The beauty of tomatoes is that they will continue to ripen after picking (not in the fridge, please) I think you should pick when the entire fruit is red and has that ripe sheen to it. Don't wait too long, or it may split, overripen or become food for animals. Green fruit should be left to ripen.


Annapolis, Md: Good Morning, Adrian.

I have about 2 dozen tomato vines in raised beds, all of them are volunteers from last year's bumper crop of heirlooms. All I really had time for this year was to thin them out and add compost- I didn't even stake them. Now I'm starting to get ripe tomatoes from these vines that have sprawled all over the place.

I don't see any more blight than usual (I pick off the yellow leaves), so should I try to go in and stake the vines to get them off the ground, or can I leave them where they are, and accept whatever crop I get? The cherry varieties are fruiting prolifically already...

Adrian Higgins: These volunteers are usually cherry tomatoes, they seem to seed most prolifically. SO if you want cherry tomatoes, fine. I prefer to pick my varieties myself, so I pull seedlings and plant varieties of my choosing. SOme seedlings may not be as good as the parent plants, if they are F1 hybrids -- another reason to buy fresh seeds. That said, yours may be delicious. I would as a matter of principle get them off the ground and away from pests and diseases.


Clarksville, Md: Hi Adrian. Do you like those newish concrete pavers for a patio or entrance, or is natural stone such as slate or flagstone a better alternative? Thanks!

Adrian Higgins: I dislike them, they represent the homogenization and uniformity of the built garden. They are done simply for the benefit of the contractor, they are uniform so you can use masons of lesser skill to install them. Bricks and flagstone, on the other hand, need a lot more hand working to fit, but it is that craftmanship that gives a garden its character.


Arlington, Va: Not knowing it was more of a bush than a typical sage plant, I planted a pineapple sage in a long planter on a balcony with several other herbs. The rest of the herbs (mint, parcel, oregano) are doing very well, but the pineapple sage seems to be having issues - it has grown rather large, but recently has a great deal of yellowing leaves with brown edges that eventually drop. Other than some of the new greener leaves at the bottom of the plant - the leaves don't smell very much of pineapple anymore. Any thoughts on what I can do to better manage the situation?

Adrian Higgins: I suspect it is in soil that is too wet. I would dig it up and place it in a nice clay pot with rich, free draining soil, and then cut it back. It should regrow nicely and the fresh leaves will be pungent once more.


Reston, Va: We just got a garden plot throught Reston Association. Wondering what we can plant at this late date and when we should start the fall crop of beans and such.


Adrian Higgins: The season is about half over, so take advantage of the weeks ahead by planting carrots, spinach, chard and beets. Try some broccoli and cabbage. In a month, sow lettuce.


Frederick Md: My tomato bushes are very bushy but also tall and have had tomatoes on them for weeks now that aren't turning red. What is going on?

Adrian Higgins: It takes sunlight and patience, some varieties take their time in ripening. You may want to trim some of the leaves so that the fruit is not shaded.


Laurel Del: Gardens have been overwhelmed by japanese beetles, I am out there plucking away, when this question came to my mind, ready?? What is the average number of offspring to each pair of beetles?

Adrian Higgins: My reference book to hand doesn't actually say how many eggs the female lays, but I'm sure it is several dozen.


Watering herbs: Adrian-

Noticed your comment in this chat that herbs need less water than shrubs/grass, and your later comment that sage may be suffering from overwatering. What ARE the water requirements for herbs? I water mine (potted) about every other day, except rosemary and thyme, which I have been told need less water and prefer drier soil. They seem to be doing OK, although teh cilantro I cut back hasn't regrown well.


Adrian Higgins: More important than the frequence of watering in the herb garden is the soil composition. It must be free draining. Raw, unimproved clay is completely incompatible with growing herbs. Even a nice loamy soil can be too wet for herbs. In preparing a bed for hebrs, I mix in lots of lots of sand and perlite and peat moss and minimize the amount of humus.


Richmond, Va: Adrian thank you for doing this chat, I have two questions for you. What would your advice be on removing Bamboo? We've cut it back, but the roots are proving to be quite difficult, and we are looking for any options short of a bull dozer. Secondly, once the bamboo is gone we would like to lay sod over the area, and I was wondering what preparations we should make to the existing dirt to ensure the sod thrives. Thanks!!

Adrian Higgins: Keep cutting it back and you might win the battle, but it will take a few years. I would stop cutting in early September, let some culms develop and then treat them with glyphosate or some other systemic herbicide formulated for bamboos or grasses.


Sterling, Va: Hello Adrian!

I planted a fairly mature honeysuckle in April, and it bloomed in May and June. However, since the hot weather has started the honeysuckle hasn't bloomed. Does it need more water, or will it just start blooming when the weather cools down?

Adrian Higgins: You may get a little repeat flowering in the summer but I suspect our climate is too hot for a good continuous show. You may wish to remove fruits and trim back stems to see if this will induce a reflowering in late summer. It may.


Gardens have been overwhelmed by japanese beetles,: Adrian,

I know you don't like chemicals, but for these persistent beetles Bayer tree and plant systemic is the answer. Protects for 12 months.

Adrian Higgins: Thanks, sometimes desperate situations require desperate measures.


Boyce, Va: hi, Adrian! what is the deal with mulch? i've heard not to use wood mulch near buildings because it causes or brings termites. true? what about using pebbles? thanks, wondering in boyce

Adrian Higgins: Termites live everywhere, and excessive mulching may indeed draw them. But mulch should not be excessive, it should be light. No more than a couple of inches, max, especially around the house.


Trimming pansies: Hi, Adrian- The Midwest (where I am) is being hit by the same heat that is all over the country. The potted pansies on my front steps are looking scraggly and tired, despite watering. I recall hearing that they can be cut back to rebloom. How does one do this without overdoing it or hurting them?


Adrian Higgins: Please release your pansies, let them go to that distant spring in the sky. They are not summer plants in the US, even the Midwest. Plant some fresh ones in late August.


West Virginia: We want to put an ornamental plant or plants in an east-facing area against the front of the house. We love crepe myrtles but don't want anything taller than 7 or 8 feet. Also like azaleas and rhododendrons but they don't seem to flower long. Any suggestions? Thank you!

Adrian Higgins: Yes, look carefully at the crapemyrtles around you. The popular tree forms like Natchez grow to 30 feet. I can't tell you how many people ask me how to cut back crapemyrtles that they think have grown too large. They haven't grown too large, they have just been placed in an area that is too cramped for them. You will need dwarf crapemyrtles, which, in time, will grow to your desired height. Abelia might be a good choice for you if you want something that flowers for a long time.


Baltimore, Md: I have a cucumber question. The vines seem to be growing pretty well and, other then some slight yellowing, the leaves and stems appear healthy. However, when the plant flowers the baby cuc's get to about an inch long before they shrivel up and turn brown. The few fruit that have matured have been good with no sign of pests or disease. Any thoughts on how to get more fruit to mature? Thanks.

Adrian Higgins: I wonder if they have been pollinated. Another reason to keep honeybees. Try and encourage bees in your garden by planting herbs like borage and lavender. Harvest the cukes young to keep them coming.


Richmond, Va: What plants work best for container gardening for a small scale apartment patio and something that I don't want to have to overwinter inside? Thanks...

Adrian Higgins: I would pick plants you can use, sweet basil, chile peppers and cilantro and parsley.


oleander: Researching this bush on the web, I read both that it is poisonous but that you would have to eat a lot of it to do any harm, and that it is so poisonous one leaf can kill an adult. Do you know which it is? I will admit to leaning toward the first, considering the popularity of the plant in the south, and the latter sounds so alarmist, but on the web it is impossible to sort fact from fiction.

Adrian Higgins: Yes, it is poisonous but so are quite a few plants in the landscape. It's probably not the plant for a garden where small children play or puppies play, but otherwise, enjoy it. We have run out of time. Hope to hear from you on the radio, or here again next week, and don't forget to check out Thursday's Home section.


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