The Garden Plot

Adrian Higgins
Washington Post Garden Editor
Tuesday, March 20, 2007; 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."

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Charlotte, NC: Hi Adrian,

Thanks for taking my question! I just bought my first house (recently moved from DC to NC). I have a small fenced in backyard that is perfectly suited for courtyard-style landscaping. The only problem is, I'm a total gardening novice - I would love to do it myself, but have no clue where to start. Do you know of any good books for beginners like me looking to design this type of backyard? Thanks!

Adrian Higgins: Camellias in time, like happy rhododendrons, grow into large shrubs, by and large. If you are continually in need of trimming, it may be the wrong plant for its space. However, you can and should trim to keep it tidy and to fix the odd wayward branch. The best time to do this is in about a month, after the flowers fade. The books say you can cut a camellia back hard, like a boxwood or yew, and it will reprout as a new and smaller shrub. Sometimes, this drastic step kills the plant. I would only do it if the camellia was in an out-of-the-way place and if its loss would not mean the end of the world.

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Washington DC: Hi Adrian - are there any plantings you can recommend specifically for improved drainage? We have a section of our yard which is constantly soggy and I would love to plant something there to suck up some of that water. The area gets morning shade and afternoon sun. Thanks.

Adrian Higgins: Conceivably yes, and it is easier to plant wet soil plants than to provide drains, although you don't want to compromise your home. Willows, of which there are many shrublike candidates, would fit the bill, as would redtwig dogwood, deciduous holly and ferns. If you have space, consider bald cypress or the swamp white oak.

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Hartford, Conn: Really quick question - when do I plant peas in my vegetable garden? I know there's some saying about St. Patrick's Day, but here in Connecticut there's still snow on the ground. How do I know when to plant?

I had a great garden last year (my first) but got it in too late for peas.

Thanks in advance.

Adrian Higgins: I would get them in soon. I would turn and amend their bed on Saturday, this will cause it to dry out and warm up, and then sow them a few days later. Grow them on trellising.

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Bethesda, Md: Thank you so much for your advice. We've been missing you this winter!

I'm wondering what to do about Russian Sage. Am I supposed to cut that back, and if so, how?

In addition, after i trim the roses, am I really supposed to put elmer's glue on the cut?

Adrian Higgins: Russian sage or perovskia can be cut back hard now. It is a summer flowering subshrub that blooms on new growth, so hack away. I cut mine to about 12 inches and remove a whole stem or two. Modern bush roses should be pruned now too. If there are any raspberry bushes in your vicinity, yes I would put Elmer's glue on the cuts to prevent a borer insect that lives off both plants from entering your roses.

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Bethesda, Md: Can you tell me a bit about the bald cyprus? I just bought a house with two 40 year old specimens and they are massive. They have shallows root systems all over the place - not nice for an avid gardener like me - and they seem to drop a lot of small branches in higher winds. How much larger are they going to get? Thanks.

Adrian Higgins: They are big native swamp trees, and beautiful. It may be that the soil is so compacted and waterlogged that it is not a hospitable place for underplantings. According to horticulturist Michael Dirr, the baldcypress grows to about 70 feet, but with great age and in the right site, it can top 100 feet.

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Anonymous: Good morning! We feed birds all winter and the lawn under the feeders no longer exists. Is there anything I could plant to cover that ground in the summer and that would withstand the scratching and seed hulls during the winter?

Adrian Higgins: I think I might go with a groundcover such as cranesbill, or even lowbush blueberries (for the birds, of course).

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Vienna, Va: We moved into our townhome about 2 years ago. We have a rhododendron in the front yard. But since we moved in, the rhododendron has not bloomed once. Can you tell me why this is? And what we can do to encourage blooming?

Adrian Higgins: It may be still too young, you may be giving it too much nitrogen fertilizer (perhaps from the lawn), the deer might be eating the buds, you may be taking off the following year's buds when you remove the faded flowers, or it may be in too much shade.

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Alexandria, Va: Hi Adrian - I would like to plant a cherry tree in my back yard this spring. Is now a good time to be planting trees? Also, the yard faces west and gets lots of sunlight from noon on. Thanks!

Adrian Higgins: Now is a great time to plant woody plants, you want some establishment and root growth before the heat of summer so it is important that the tree be planted correctly. I did an online slide show on the proper techniques that hopefully you can find in the Home and Garden section of our website. Make sure you understand the eventual spread of whichever tree you pick, and plant it with sufficient elbow room.

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Park View, DC: I hate to even have to ask this question, but I must. Due to a new dumpster associated with the apartment building behind my house added to the virtually abandoned garage next door and compounded by a relatively mild winter, rats have taken over the rear of my yard and are plotting a world takeover from there. I can put poison all over my own yard but it won't solve the problem.

But where does that leave my vegetable garden? I'm reluctant to plant because -- well, ick! I don't want to eat anything a rat has touched. On the other hand, my vegetable garden, such as it is, brings me great joy. Do I have any options? This is really bumming me out. Thanks.

Adrian Higgins: I would be leery of starting a vegetable garden if you knew you had a rat population. I think I would call the city ratcatcher and not try to lay poison yourself. This might be the year to plant perennial herbs and vegetables, such as asparagus, grapes, horseradish and figs in the hope that when they fruit, the rat problem will have gone away.

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Need a tree, DC: Adrian,

Thank you for doing these wonderful chats! We are hoping to put a tree in our front yard to add some dimensionality to our yard. We are looking for a thin, vertical tree and are thinking about cheating with a crepe mytrle. Thoughts of suggestions? We don't want it to get too big, but we'd like to buy it relatively mature to add instant aesthetic value.

Also, we planted ivy on our steeped lawn nearly two years ago and it's still in miserable shape. I thought ivy was supposed to grow with monsterous ferocity...not in our case! Suggestions?

Thank you Adrian.

Adrian Higgins: Crape myrtles are not upright, they are spreading vase shaped and occupy a lot of real estate after a few years. I would try an upright hornbeam or even a ginkgo tree (try to get a male clone). Trees planted when young are not set back so much as larger specimens and they soon catch up in scale. English ivy is now considered an invasive weed. I find it rather dull as a ground cover. I would rip yours out and statr again with something like, cranesbill, liriope, leadwort, even deadnettle.

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Charlotte, NC: Hi Adrian,

I may be mistaken, but I think you answered my question with a response to another poster's question. Here's my question again - would love some info - thanks!:

I just bought my first house (recently moved from DC to NC). I have a small fenced in backyard that is perfectly suited for courtyard-style landscaping. The only problem is, I'm a total gardening novice - I would love to do it myself, but have no clue where to start. Do you know of any good books for beginners like me looking to design this type of backyard?

Adrian Higgins: It was either a technical glitch or you have discovered I have left my eyeglasses in the car. I would go out and buy a book called The Small Garden by John Brookes. The key with small townhouse gardens is to marry the outdoors with the inside in some fashion, to use plants of the correct scale (read small) and pay a lot of attention to detail.

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Alexandria Va: Good morning, Adrian.

The smallest of four backyard hemlocks which provided a nice screen for the house succumbed to last summer's drought. Would you recommend a fast growing evergreen replacement? Thanks!

Adrian Higgins: No, I would recommend a slow growing evergreen replacement, such as Hinoki falsecypress, a chamaecyparis pisifera, or Japanese black pine. A fast grower like Leyland cypress will prove a maintenance nightmare unless it is sheared twice a year into a clipped hedge.

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Del Ray, Va: I have a 2 year old Rosemary plant that I'd like to move - when is the best time to do it, and how should the soil be prepared?

Should I be adding sand or manure/compost?

Thanks!

Adrian Higgins: Rosemary plants survive in dry climates by sending roots down deep. You will be risking its death by moving it. If you try, I would cut back some but not all of the top growth in the process. I would get a young plant now and stick it in. Rosemary plants don't need heavily enriched soil but they hate poor draining heavy clay soil. I would mulch with pea gravel.

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Chantilly, Va: Adrian,

This will be the third year for my weeping cherry. So far, it hasn't grown much in height, but the umbrella is forming beautifully.

Do you think this will be the year for some gain in height ?

Also, had great luck with the Bayer systemic for trees and bushes. Kept the beetles away from everything.

Adrian Higgins: The grower seeks to achieve instant height by grafting the weeping bit on to a tall trunk of rootstock. This can look rather artificial, so be patient and let the tree assume something resembling a natural shape in its own time. Do not trim all the pendant branches evenly. You might as well stick a mop in your garden. I think this systemic pesticide probably is one method of reducing damage from Japanese beetles. Not sure it would be my first response.

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Kensington, Md: Hi Adrian,

I noticed this year that many of my japanese boxwoods and hollies have what looks like freezer burn on many of the leaves. In some cases it appears that new growth that happend late last year have died. On my needle point hollies many of the leaves are dead and some appear with black spots.

Should I jsut cut out the bad areas or wait for mother nature?

Thanks!

Adrian Higgins: I believe the conditions in early winter were so mild that broadleaf evergreens did not harden off their foliage before it turned really cold in Feburary. You will see a lot of damage if you look for it, though it will grow out this spring. I would wait for the new growth in April and May and remove the damaged foliage then if necessary.

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Deer damage: Hi Adrian, thanks for taking my question. The deer have been eating our azaleas and, after a few years of deer damage, the azaleas are looking very scraggly (at least I assume this is from the deer damage). I've found a great deer repellent, so rather than replacing the azaleas, I'm wondering if we can do something to make them pretty again. Any suggestions?

Adrian Higgins: I believe the right repellent will work if applied preventatively and reapplied after each heavy rain. This is a big commitment for two weeks of blooms. You may want to consider an alternative shrub.

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St. Paul, Minn: Hi Adrian,

I actually planted the many bulbs I bought from a catalog last fall (daffodils, hyacinth, and tulips) but covered them with maybe 4 inches, give or take, of wood shavings. Now that spring is around the corner up here I am concerned they won't be able to make it through that much cover. Also, are they still in danger of squirrels? The benefit is the squirrels didn't seem to find them so deep.

Adrian Higgins: The bigger problem is that if the wood shavings are still green they may be extracting nitrogen from the soil as they decompose. I would scratch around and apply a little bulb food to your emerging bulbs. When is bulb season in St. Paul, June?

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Silver Spring Veggie gardener: As I do every year, I got out early in March and planted seeds for peas, parsley, cilantro, swiss chard, and leaf lettuce. But then we had snow and ice all that other misery. Should I replant any of those things? I can see the parsley has sprouted but there is no other action. My crocus have rebounded and the tulips are several inches of green now, if that is any guide to the climate in my yard. Thanks!

Adrian Higgins: If you are not seeing germination in a couple of weeks, I would try again.

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Washington DC: Where is the best selection native plants in the DC area?

Adrian Higgins: I believe Green Spring Gardens in Alexandria hosts a native plant sale each spring. Check out their website.

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Annapolis, Md: Hi Adrian,

I planted a number of flower boxes last year on the deck, and left the soil in them over the winter. Is this still usable, or should I throw it out and start over?

Thanks for your help!

Adrian Higgins: Don't reuse old soil, it's a false economy. Throw it on the compost pile or use it as a garden mulch. Soil in pots becomes compacted, depleted in nutrients, and suffers from a build up of fertilizer salts. Use a fresh potting mix.

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Alexandria, Va: I've always had a small veggie garden, but not been too creative in what I grow..never grown peas or green beans...are these hard to grow from seed? what are the tricks for doing this?

Thanks.

Adrian Higgins: Beans are fine, and I prefer pole beans, because you can grow more in a given area and they are cleaner and happier. Peas are tough because we live on the southern fringe of English pea territory. Get them in this weekend and hope that when they flower and fruit in May into June, it remains relatively cool. Some years are great for peas, others not so.

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Gainesville, Va: Hi Adrian-- Last summer, my tomato and bell pepper plants were prolific, but the fruit never grew any bigger than ping-pong balls. The peppers, in particular, seemed pretty puny. These were the same varieties I have used before, with grander results. Any tips for growing them bigger this year? Thanks.

Adrian Higgins: Peppers, especially sweet peppers, take ages to develop and mature. You want them in after the frost but not too long after, so they begin to fruit by mid summer. I would also add a superphosphate fertilizer, and make sure they are in a good sunny location, evenly watered and kept free of weeds.

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Fairfax, Va: Adrian,

Any advice for the grass this time of year ?

Adrian Higgins: Get a lawnmower, or a goat. You can seed patches now, but I would leave a wholesale rejuvenation until late summer.

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So. Maryland: Mr. Higgins: Help! I have several large clumps of Carex (sedge) that are growing larger. Can I cut back the Carex as I cut back liriope? Is now a good time to divide it?

Adrian Higgins: Yes, sedge should be cut back now.

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Bethesda, Md: My annual tomato problem: Why am I getting 6-foot-tall plants with little fruit and thin foliage? the plants look scraggly at the bottom. Should I be cutting off the growth tip or something?

Please help!

Adrian Higgins: I have come to believe that our summers, ironically, are too hot for tomatoes, so I would urge people to get their seedlings in early, again after the last frost, so that they fruit in July into August rather than August into September. You can also sow plants again in late May so that you will get a fall crop. Also, consider determinate varieties that will fruit in one heavy go.

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Richmond, Va: I noticed that I didn't do a very good job of dividing daylilies in the fall. Is it too late now? And I have what I think is Creeping Phlox that runs around the rocks that edge my garden. Is there something else I can add that blooms later in the season? Thanks for your help.

Adrian Higgins: You can still divide daylilies, though the blooming may be diminished this summer. I would try some Mexican zinnia and or delosperma to extend the season of bloom in the rock garden.

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Window Box Soil Reuse Follow-Up: Thanks for taking my question! As a follow-up to the reuse of soil in boxes, I have a question about herbs I had planted in a window box. Does your advice still apply if I have oregano and thyme in a box, since they're perennials? They seem to be doing just fine, but should I supplement the soil or replany them in new soil?

Adrian Higgins: It may be worth digging out the oregano and thyme, replenish the box, and replant them.

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New to the game: I'd like to plant some groundcover around a maple in our front yard. Pachysandra is there currently, but I find it a bit dull. Any other thoughts for some shade-loving, quick-growing ground cover? Thanks!

Adrian Higgins: Maples are tough, lots of surface roots. I would grow something called epimedium, which will tolerate dry shade, but you will have to be patient. They take several years to fill in.

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Washington, DC: I live on Capitol Hill, and I am looking for somekind of shrub to plant in my front yard. I'd like it to be about 5 feet high, 5 feet wide, not too much maintenance or too many roots. It would get plenty of sunlight. Not sure what to plant or when to do it.

Adrian Higgins: There are dwarf forms of crape myrtle that would work for you.

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Burke, Va: Hello Professor. I enjoy your chats and have learned so much from them. It seemed they disappeared for a while but am so glad to have them back.

I have a very small vegetable bed in the back yard of my townhouse. My husband and I are expecting our first child at the end of April, so I don't expect to have much time in the garden this year, but don't want to leave it bare. Can you suggest some easy, low-maintenance vegetables for our plot? Or is this perhaps a good year just to plant a nitrogen-fixing cover crop to work in in the fall, and return to vegetables next year when I'll have more time (I hope)?

Adrian Higgins: I would perhaps plant some raspberry bushes, some alpine strawberries and some asparagus. All should be fruiting well when your youngster becomes a full fledged gardener at the age of two. We've run out of time, alas, but Tuesday roll around more quickly now that they have changed the clocks. See you next week.

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