Adrian Higgins

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The Garden Plot
Hosted by Adrian Higgins
Washington Post Garden Editor
Thursday, April 25, 2002; 11 a.m. EDT

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.

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."

Greenville, S.C.: I bought several no-name, small azaleas from the Garden Dept. at Lowe's four or five years ago. For the couple of years, they had lovely pink blooms in the spring. Last year and again this year, there have been no blooms at all. Other azaleas in the garden are flowering to beat the band. What to do? Thanks.

Adrian Higgins: They are either in too deep a shade, though unlikely, you would see a sporadic bloom or two; or you have pruned them after they set buds last June, or an animal has done that for you, perhaps a deer.

Arlington, Va.: Help me, please!

It's not an outdoor garden question, but hopefully if you have a minute, you can answer this question. I have multiple indoor plants: ivy, aloe, regular potted plants I unfortunately don't know the name of. I also have numerous little bugs/gnats/critters that fly around constantly. Do you think these bugs are from the plants/water? They are very annoying. Is there anyway to get rid of them if they are plant related without trashing the plants?

Thank you!

Adrian Higgins: The first step in dealing with a pest is in identifying it. Green, black or red soft bodied insects are aphids, easily controlled with a simple spray of water or insecticidal soap. White fly is a moth that is a pernicious greenhouse pest, it can be a problem outdoors too. If you have white fly, take the plants outside and spray them with horticultural oil.
Mealy bugs are segmented pests that cover themselves in a waxy, cottony down. They often hide beneath leaves. You can kill them with rubbing alcohol on Q-Tips, but the insect also dwells in the soil. If you have a bad infestation, repot your plant using a soil mix containing a systemic pesticide called imidacloprid. Bayer brand makes such a product. They key to bug control on house plants is to police the plants often and eradicate pest populations before they get out of hand.

Chevy Chase, Md.: Hi Adrian. I'm thinking about growing some food on our apartment balcony. The balcony faces north and gets a fair amount of wind at times (I'd say up to 50 mph occasionally). Would it be feasible to grow tomatoes and peppers, maybe some basil? If not, is there anything else you recommend? Thanks.

Adrian Higgins: I can't think of a worse environment for a vegetable. You might be able to grow some parsley or chives. Otherwise, look for a community vegetable garden with some sunlight.

Bethesda, Md.: I would like to include a lot of ornamental grasses in my garden, but I'm worried about adding to a problem with invasive species. For example, I think fountain grass has a bad name in some places for re-seeding everywhere and pushing out native wild plants. Which grasses should I avoid in my region?

Thanks, Cindy

Adrian Higgins: I think the two that can be a problem are miscanthus and pennisetum. They seem drawn to water and apparently can grow in drainage ditches and the like. If you don't see any growing wild in your area, I think you can grow them without concern. The real weedy grass (besides bamboo) is Arundo donax, but that is not often sold as an ornamental.

Maryland: Adrian,

I have ivy that I am trying to grow into a topiary. What type of fertilizer should I give it? and recently I've notice brown spots with white centers on the ivy leaves. What is it? and how do I remedy it?

Thanks!

Adrian Higgins: I don't know what it is without digging into the books. A couple of things come to mind: Slug damage can cause brown spots, otherwise it might be damage from chemical sprays or a bacterial leaf spot. Alternatively, the recent late freeze may have caused some damage. Variegated varieties and hybrids can be less hardy than plain green Hedera helix. In any case, cut off and remove the affected leaves. Water only the roots and skimp on the fertilizer. Ivy is pretty indestructible.

Fairfax, Va.: I have a small stump in my garden that I'd like to se go away. Its roots are under a patio, so diging it up is not an option. What Can I do to help it rot away?

Adrian Higgins: If you take a sharp axe, or, better yet, get someone else to, you can slice through the roots that go beneath the patio and then dig out the stump. Otherwise, chisel out a hollow and use it as a container for some annuals. The constant watering will undoubtedly hasten the stump's retreat.

Cheverly, Md.: I just bought a house in January and have a yard for the first time. I was planning on having California poppies in my front yard (southern exposure) but recently learned that while they are draught tolerant they may not be heat tolerant.

What do you think?

Adrian Higgins: I have not grown the California poppy, Eschsholzia californica, but am told it will work here. It is a short lived perennial that requires well drained soil, it might even benefit from a little afternoon shade here.

Gaithersburg, Md.: I've started some vegatables by seed indoors. All of my tomatoes are in those brown biodegradable cups, but they're looking sort of peeked, while everything else looks great. They're kind of small and slightly yellow -- and sometimes it looks like there is some hairy mold growing on the outside of the pots/cups. What should I do?

Adrian Higgins: I am in the same predicament. I have reached the conclusion that seed starting requires at a minimum a professional high intensity discharge lamp and, better yet, a greenhouse. Shop lamps don't work well enough.
The first thing your seedlings need is light, so put them outdoors but in a spot sheltered from afternoon sun and from wind. Bring them in if nighttime temperatures drop into the 30s or 40s. Once the soil warms, in two or three weeks, plant them deeply, and they should respond.

Woodbridge, Va.: Besides aesthetics, what are the pluses and/or minuses of mulching with pine needles?

Adrian Higgins: I think pine needles are an excellent mulch. People fear that you make the ground too acidic but I think that is an overstated fear. Just make sure you don't have the layer more than three inches deep.

Washington, D.C.: First time homeowner and gardener. Looking for a one-stop plant shop that can give great advice to the novice and also sells somewhat UNUSUAL plants and flowers. Any suggestions? I don't want the same garden as my neighbors. Thanks

Adrian Higgins: I think if you visit good retail nurseries you will be surprised by the selection available today, vast enough to let you grow something unique. There is a line of annuals called Proven Winners which are meant to be new improved and high performing plants.
Incidentally, there is nothing wrong with using common plant material, especially if you are new to it. You want to start with something that has some tolerance for inexperience. You can take common plants--marigolds, petunias, and even (aargh) begonias--and use them well together.

Washington, D.C.: A couple of weeks ago somebody asked about a palm that is hardy in the Washington, D.C. area. He was probably referring to Rhapidophyllum hystrix, the needle palm. Although it is a true palm this species is trunkless, forming a large evergreen suckering "shrub." Plants are hard to come by and are usually expensive because they are very slow-growing.

Needle palms are fully hardy in zone 7a without protection, and marginal in 6b; there are several well-established specimens around the city. There is a large specimen at the National Arboretum that has been growing there for many years.

Adrian Higgins: Thanks. Passing this along.

Richmond, Va.: I would like to add some height to my containers this year, I bought some supports suitable for vines. Can you recommend some flowering vines suitable for a container and maybe some other plants that would do well as companions? The container is about 18” square and the support is about 3’ high.

Thank you!

Adrian Higgins: To me height means at eye level, six feet or so. I would stick in a mandevilla or a gloriosa lily.

Alexandria, Va.: When can we plant basil? Pepper plants?

Adrian Higgins: In Alexandria, I think it is safe now. Both will just sit until we have had a week or two of good heat to warm the soil. Cover them if we get another night like Tuesday's.

Pasadena, Md.: I am concerned about a strange liitle bug that is living on my Indoor Ivy Plants. The little bugs are white and create a "spider web" around the leaves. How can I treat this plant? Thanks!

Adrian Higgins: Webs are usually associated with spider mites, which tend to be red. There might be white species, my friend Scott Aker would know. In an case, take the plant outdoors and hose it with a stiff jet of water.

Woodbridge, Va.: Which flowers are the best for a south balcony, which means sun from in the morning trough late afternoon.

Adrian Higgins: Anything in a container will dry out quickly, especially in a south facing balcony. I would plant something that is suited to hot and arid conditions. Hens and chicks, santolina, sedums, thyme, all come to mind.

Ugly Ivy Help: We are new homeowners and new gardeners, as a result. Here's our problem: Our front yard is mostly level but then there is a steep (probably about 65 degree) dropoff of about 6 feet to the street. On the dropoff there is ivy planted. We keep it trimmed but parts of it are turning brown and it's awfully ugly at this point. We would love to rip it out and plant grass but are concerned about mowing it at that angle. How difficult would it be to rip out the ivy and put in something more attractive? Is grass really feasible at this location? It does get plenty of sunlight. Is there another low-maintenance plant that would be better?

Adrian Higgins: Ivy does get a leaf spot disease. I think the general control is to simply cut it back and let fresh leaves appear. Your hill is too steep for turf. The soil would erode before the turf took hold and mowing it would be a hazard.
Within the ivy, plant a few plugs of showy evening primrose, Oenothera speciosa. It will spread and smother the hillside in May with pink flowers. Once it is established, you can pull the ivy, bit by bit.

Stumps: The person trying to get rid of a stump might want to look into getting it ground out. Some tree services do this and they can get into some small places. I had a big stump ground out of a corner between my house and a stone wall. Not sure how big the stump needs to be for this to be practical.

Adrian Higgins: Thanks. I think I'm back on line now.

Arlington, Va.: When is the earliest I can plant tomatoes? I planted last year after Memorial Day, and they didn't get established -- I think they were stressed by the heat. (We're also going to put in more topsoil this year -- there was too much drainage at that site.) Thanks!

Adrian Higgins: If you're an early bird, you can plant now or next week. I plant between now and early July to assure crops through to frost.

Ohio: I'm a first-time homeowner this spring and have finally bought a lawnmower! It is a mulching model but the grass is so long I think I will bag the clippings from the first mowing. What should I do with them? Spread them over my still-vacant planting beds? Throw them away?

Adrian Higgins: Spread them over the beds as a mulch. At this time of year you may have to mow more than once a week to avoid stressing fast growing turf. You shouldn't really take more than an inch off at a go.

Owings Mills, Md.: Adrian,

I love your show and mark my calendar so that I never miss a session. Great info. My problem is that I have a King Sago Palm which isn't doing too well. The problem is that it sprouted new growth which grows up in a stalk and then I assumed was to open into new growth. The new growth/needeles has not developed and the old growth is dying off. What should I do? I would hate to loose it since it was somewhat expensive.

Adrian Higgins: The Sago palm puts out new growth every other year. Be patient, it takes a few months for the fronds to unfurl fully.

Re: Greenville, S.C.: As far as the non-blooming azaleas are concerned, isn't overfertilizing and/or fertilizing at the wrong time of year a fairly common reason for blooming plants not to bloom?

Adrian Higgins: Possibly, but you would have to gorge it with high nitrogen fertilizer to diminish blooming.

Portland, Ore.: My husband and I are new to gardening and clueless but enthusiastic. Can you recommend any great books for beginners with not a lot of time?

Also, we bought a bunch of annuals this weekend, and it's been pretty warm here this spring. If I go ahead and plant them this weekend (we get a delivery of compost with which to amend our clayey soil on Friday), is there any way to protect them if the weather turns colder? Right now they are in their plastic containers, kept moist, and I put them outside in the morning and take them in at night.
Thank you!

Adrian Higgins: Make sure the soil is well amended and raised up so that it doesn't sit waterlogged and get cold. The object at this time of year is to warm the soil as best you can. Annuals should be all right as long as it doesn't dip below freezing. I would not plant them until after your last average frost date for your district.

Merrifield, Va.: Hi -- I'm getting my kitchen garden set up, and this year I want to put in underground irrigation (ooze tubing). I haven't remediated my soil much. It's mostly the clay you find here, but I will till in compost, and maybe some builders sand or gypsum, lye. The plot has a slight downward slope.
My questions are, noting the soil, what width of area should I expect one length of tubing to water? One length of ooze tubing per 2' bed? How deep should I bury the tube? Do I crank the water through it, or let it dribble?

(If it makes any difference, I'm growing corn, sunflowers, pumpkins, butternut, peppers, basil, tomato, artichokes, kale, chard, herbs)

Thanks!

Adrian Higgins: The more soil work you do, the more efficient and successful will be the drip irrigation system. Lay it on thin soil, even under a mulch, and it will simply not be well absorbed by the ground and will run off. After you have improved your soil, and before planting, rig up the drip irrigation, run it, and see how well it works. Adjust the network and water flow as needed, then sow your seeds.

Bethesda, Md.: Hello --

I am a new home owner and I thought that your book "The Washington Post Garden Book" looked like something I needed but I have been unable to find it in any stores. Is it being republished? Thanks.

Adrian Higgins: I would hope that it is still available. Last time I went into Borders, it was available. Check on the in store computer.

Washington, D.C.: We are placing 20" flagstones in our yard. What's the best way to make sure the stones don't move around? (Our yard is slanted, not flat.)

Adrian Higgins: Flagstones need flat or almost flat ground and to be set on a four to six inch layer of compacted gravel or stonedust. Otherwise, they will wander. I am sorry that I could not get to all your questions, but keep them coming next time.

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