The Garden Plot
Hosted by Adrian Higgins
Washington Post Garden Editor
Thursday, Oct. 19, 2000; 11 a.m. EDT
Adrian Higgins will be online Thursday to field your questions and comments concerning gardening and horticulture.
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."
Below is a transcript of today's discussion.
Editor's Note: Washingtonpost.com moderators retain editorial control over Live Online discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions.
When would be the best time to relocate the following plants: goatsbeard; queen-of-the-prairie; and milkweed? I think my problem with all three is that they aren't getting enough sun. They've all grown some since I first planted them - the goatsbeard in spring '99, the other two this last spring - but haven't flowered. I would like to wait until spring to find a new place for them but wonder if it's better to do it now. Thanks for any advice.
Adrian Higgins: I don't know queen of the prairie but the goatsbeard needs evenly moist soil and in our latitude some protection from the afternoon sun. Milkweed likes full sun and well drained soil. Now is a good time to lift and move them. Give them a good drink and a mulch, they should spring back next spring, no pun intended.
Can you suggest an evergreen that will grow at least 10 ft tall in the shade?
Adrian Higgins: A hemlock or a Hick's yew are about your only conifer choices, if you want a broadleaf evergreen, the choices expand dramatically. Certainly many hollies fit the bill (larger ones such as American holly; one called Ilex kohneana; the Burford holly (not Nana;) and the yaupon holly.)
When is the latest reasonable time that tulip bulbs can be planted? As my gardening is restricted nowdays to weekends only, and I have plans to create some new beds, I won't be able to set any bulbs for at least a few weeks. Thanks.
Adrian Higgins: Most tulips can go in as late as December in our Zone 7, the risk is that the longer you wait the greater the chances that a cold snap will freeze the ground, though unlikely this far south. Early season tulips, though, should go in now. These include most species tulips and Greigii types.
Round Hill, VA:
Hi, not quite a gardening question... I have a red "dust" on my grass and have never seen that before. I found information on white, gray and black grass molds, but no red! Is this just another type of mold? It's in areas not directly under trees so not associated with the falling leaves.
Adrian Higgins: It is probably either rust or a red smut. Take a sample to your local extension office, they will diagnose the problem and recommend treatment.
When my husband began looking for an opportunity to relocate in his chosen field a couple of years ago, I gave him one restriction: it had to be in a gardening zone 6 or 7, preferably in a state bordering the Atlantic. After 14 years of gardening in zone 8b (the Florida panhandle), I wanted to try bulbs and peonies and lilacs and clematis! I wanted to keep crepe myrtles, but I wanted vivid fall color! As a Mississippi native, I wanted some snow, but not weeks and weeks of it.
I was THRILLED to find a well-maintained and beautifully decorated townhouse with a 25'X40" back yard that is basically empty, with a few poorly placed shrubs and perrenials around the edges. I feel like I have been given a blank canvas!
I will be buying your book today, but my immediate questions are these:
1. I have two peonies growing in a terrible spot--practically behind a hydrangea, about 6 inches from the privacy fence. When and how should I move them? I think I remember hearing that peonies don't like being moved--is that true? Also, they look pretty bad--is that normal for this time of the year?
2. There are six hostas in a row like toy soldiers in the front bed between the parking areas, right in the hottest and sunniest spot I have. They also look terrible--they are big, but every leaf is half-burned. When and how can I move them? Can they go in the shady spot under the deck, along with the native ferns I brought from Florida?
Adrian Higgins: I am glad that you made your husband see sense. In a space as small as yours, every plant must be thought out and merit its place. Don't keep existing stuff if it doesn't fit your bill, though I am sure the ones you mention will. It is difficult to suggest a plan sight unseen and off the cuff, but do not make the mistake of trying to exploit the space by having an empty middle and narrow beds squeezed to the side. Build a comfortable patio and allow for generous beds that extend into the space. Develop an enveloping cocoon of vegetation. Do not try to fill it with too many accent plants or specimens, or too much large shrubbery. Scale should be foremost on your mind. Use just one or two specimens and a few accents and then fill in the spaces with plants that will recede or just do their thing at certain moments of the year. The range of hardy bulbs is enormous, know though that most hybrid tulips will not reliably perennialize so use them as annuals. Peonies don't like being moved, but now is the time to do that. Make sure that the crown of the plant is buried, but no more than two inches or blooming will suffer.
All hostas look bad now. They will take sun if properly watered and may not like as much shade as the ferns. Good luck, sounds exciting and because the space is small, the project is not overwhelming. Please tell your husband that in D.C. it is customary to spend half the value of your home on the garden. This is a lie, of course, but he won't know if we don't tell.
Great Barrington, MA:
Is it too late in zone 5 to dig up and divide Siberian Iris?
Adrian Higgins: I am afraid it is probably too late for you. Irises are best dug and replanted in September. They need warm soil to grow fresh roots so they won't rot over the winter. You could chance it with a heavy mulch and in a site that is sunny and well drained, but it will be a risk.
Thanks for the advice on the goatsbeard and milkweed. Queen-of-the-prairie is known by another name - filipendula, maybe? One more question - you wrote that the goatsbeard would benefit from evenly moist soil. Could you explain what that means? Never let the soil dry out?
Adrian Higgins: Filipendula is a perennial that requires full sun and even moister, nay, wetter soil than goatsbeard. What is evenly moist soil? It is soil that has been enriched with humus and has the consistency of a sponge. Plants that need it also need watering during periods of drought. Poor clay soil in exposed sites is not for these plants.
I know this is more of a spring questions, but I want to prepare. I have a blue-ish grass that overtakes some of the beds I have in my front yard. It roots underground and I spent days pulling it all up just to have it re-appear. Someone said it was crab grass others said iron weed. I think the roots look like miniature bamboo roots. Now I am seeing it growing on my lawn. What is it and what can I do to get rid of it in beds and on lawn?
Adrian Higgins: You have Bermuda grass. It is virtually impossible to eradicate because it doesn't respond much to weed killer and the roots run deep. It likes dry soil and it dislikes shade, so if you can grow your desired grass in pretty good topsoil, aerate it frequently, and mow it at three inches, it will keep the Bermuda grass at bay. This is not to say that you should try to rip out or dig out large patches of it. Now is the time to do that, so you can reseed with a cool season grass such as turf type tall fescue.
Can a scented geranium survive the winter in the ground? If not, will it survive if I bring it in the house for the winter? I have one outside in a 10" pot and it grew like crazy all summer, about 18" high and almost 3' wide, but I only got a couple of teensy-weensy flowers. I'd like another shot next year at trying to get it to flower. Thank you for your help.
Adrian Higgins: No, it is not hardy. You will have to bring it indoors, keep it in a bright, cool room, water occasionally, but not too much, and stop feeding. You can cut it back next April and set it back outside. Keep pinching the new growth then to promote bushiness. These geraniums are grown more for their foliage ornament than flowers, which are a bonus.
I have a small garden bed in my back yard (probably 3 ft by 12 ft) that gets a fair amount of morning sun then is shaded in the afternoon. It was full of weeds when we moved in and I have gotten it all cleared out now, but I would like to know how to rejuvenate it and what might be good perennials to plant there. I have a toddler so I need things that are fairly easy to care for. Also, are there things that I could plant as late as early November and have them come up in the spring? (baby's going to grandma's in November so I'll have a whole free weekend to work on the yard, yay!)
Any advice you could give a new and sporadic gardener would be greatly appreciated!
Adrian Higgins: Three by 12 is pretty small. Consider enlarging the bed so that you are not forced to plant things in a row like a line of soldiers. It is hard to recommend things without knowing what is behind this bed. If you have a fence, consider growing a climbing hydrangea, which is slow growing but worth the wait, and desirous of afternoon shade. Beneath it, grow some low growing ground covers such as liriope, sweetbox, ivy, hosta, or creeping jenny.
My grass just looks terrible! We are on the coast. What type of grass would you recommend for this zone and how would I go about changing it?
Adrian Higgins: This weekend might be your last chance to fix the grass up thar north of the Artic Circle. We struggle with cool season grasses in Washington, but you don't have to: There are many improved varieties of turf type fescues as well as bluegrass varieties, you can mix them and should. Check with your local extension office for a list of recommended varieties. Don't succumb to buying cheap or unnamed varieties at the hardware store, there really is a difference between varieties.
Ellicott city, maryland:
I saw the question above where you suggest some hollies and I have another holly question for you. I am thinking of planting some Nellie R. Stevens Hollies as buffer between my backyard and a road instead of Leyland cypress. The location is sunny. My main question is this- I've been told that these are fast growing hollies. What does that mean? If I buy some that are 3-4 ft tall right now, how long until they are 6-8-10 ft?
Adrian Higgins: Nellie Stevens probably grow, in good soil and with water, at two feet a year. A much better choice, I might say, than Leyland cypress.
I love lavender, but live in an apartment. Do you know of any local growers who sell either fresh or dried lavender on the stem? I've looked at farmers markets, but no luck. Thanks.
Adrian Higgins: Herb societies have sales in the spring, when retailers also stock fresh lavender. Live lavender at this time of year looks rather bad, to say the least. If you have a balcony or a sunny window, consider growing live lavender. There are herb farms around and I would think there would be lots of dried lavender now available. You may have to go to a florist's. Ask at your next farmer's markets if there are any herb growers and when they sell their wares.
The small bed is along one side of our back patio. There are also beds around the perimeter along the fence, but they are mostly shady and filled with azaleas and other such things. I also have a patch of blck eyed susans in one spot.
Anyway, the small bed is just empty for now, with a brick border and against the patio on one side, open yard on the other, with a tree a few feet away in the yard.
I had thought about just filling it with bulbs, but then I'm not sure what it would look like after they're done blooming!
Adrian Higgins: Plant early bulbs such as grape hyacinths and crocuses and early daffodils and then later flowering ones such as mid and late season daffodils, tulips, and alliums, and then plant perennials that leaf out late above them: namely daylilies, Japanese anemone and leadwort.
If I tell my husband the Washington standard for garden expenditures is half the value of the house, my husband will be thrilled to know I am cutting back...
Does Japanese Roof Iris do well here? I brought some from Florida--I love the delicate sprays of blooms like miniature orchids and the year-round handsome architecure of the leaves.
Adrian Higgins: Great answer. Yes Japanese Roof iris will do well here. Give them a mulch to protect them over the winter but then remove it in the spring (it harbors slugs). You will need to patrol for these mollusks as the fresh growth emerges. They will, I should say, probably lose their leaves in a really bad winter, but will bounce back.
Silver Spring, MD:
We have a new problem the last few weeks. Mole ruts everywhere, destroying our lawn. I think until this point in time, there must have been a neighborhood cat taking care of this problem. What do we do?
Adrian Higgins: REpellents and gizmos that send them crazy tend not to work. You can get traps to place in their tunnels, which kill them. Cats do a good job of keeping down mole, mice, and vole populations.
I have a very small bed in my city backyard: roughly 4x10. I can't make it any bigger because of the yard size. Is this too small for a vegetable patch?
Adrian Higgins: No, but you would need full sun and if you have fences all around you won't have enough light, I would think. You can grow some veggies in partial shade: lettuce, spinach, parsley and carrots come to mind. A way of extending the space and getting more light is to build trellises and grow up them such things as pole and runner beans, tomatoes, and cucumbers.
I have a mature pine tree (15+ years) with a
problem around my new home. About 4 years ago the top branches all grew out at an angle and a leader was never established to continue the trunk upward. It has grown that way ever since (sideways) and now the top branches are starting to bend downward. I have been told this will eventually kill the tree. What can I do to save this tree? Thanks.
Adrian Higgins: This is why you should keep an eye on all young trees and especially conifers to make sure they are developing a good leader. The standard advice is to remove all of your top laterals except the strongest and then train it into a new leader. Tie a splint to the top of the trunk, bend the chosen lateral skyward and tie it with soft twine. (Don't use wire or nylon string, which will cut into it).
I am just a balcony gardener. Can I plant bulbs in a large clay pot for spring flowers or does the soil get too cold?
Adrian Higgins: Either use a whiskey barrel, which has enough soil to minimize rapid changes in soil temperature, or wrap your pot in some form of insulation. Bubble wrap works OK but looks rather strange. Your soil must drain.
For the Lavender seeker, try Smile Herb shop in College Park, the Cash Grocer on King Street in Old Town Alexandria, or GreenSpace Garden Center on Rt. 1 in Hybla Valley.
Adrian Higgins: Thanks a lot. I hope to write a piece in the coming months about herb growers.
Regarding lavender: A certain lotion-and-potpourrie chain store at Pentagon City sells bags of lavender buds.
Question: I have a few Skimmia Japonica and one has a terrible case of what I guess is scale. (Stems are covered with little white flakes, looks like laundry detergent flakes.) The others have a small amount. Should I yank out the really bad one? And how should I treat the others? Thank you!
Adrian Higgins: Don't remove it unless it is dead. Buy some horticultural oil and a sprayer and smother those beasts now. Keep the plants well watered going in to the winter.
A quick lawn question - we were a bit late in getting our seed down (overseeding an existing, patchy lawn) - just last weekend. Now the leaves are falling. Is there any chance that we will get results before cold weather sets in? Or did we just feed the birds? Thanks!
Adrian Higgins: No. A mulch of straw keeps the ground moist and discourages birds. YOu will have to gingerly remove the leaves as they fall. Blithe raking will undo your work. You may have to use a plank to walk on and then pick off the leaves by hand, assuming the space is small enough.
Even with high fences, the writer with the small space may be able to get enough light for veggies--I hung mirrors on trees, fences, and walls in a previous garden, and used white or creamy rocks, fences, ornaments, painted furniture to intensify and reflect enough light to have a butterfly garden in a shady spot.
Adrian Higgins: Terrific enterprise, thanks for sharing.
Can you successfully grow oregano and rosemary indoors? I only get a little sun through the windows in my townhouse...
I think I must be overwatering the rosemary even when I grow it outdoors it dies. (I'm on plant number three)......
Adrian Higgins: Houston is tough territory for rosemary: the air is too moist. Put it in well drained, alkaline soil in a spot that gets good air circulation. It sounds as if you don't have enough light to grow these marvellous herbs indoors.
Is there any benefit to surface application of bone meal on areas where Spring bulbs have already been growing over the past years? Thought being that the nutrients would eventually seep down into the soil during the fall rains and thus provide beneficial nutrients. Also, when planting new bulbs, is it best to apply the bone meal at the bottom of the bulb or to mix it in the soil at the sides and top?
Adrian Higgins: I have a little tip on this in today's HOme section. One of the most eminent bulb authorities in America, John Bryan, tells me that fertilizers planted with the bulbs do little good because they have leached by the time the roots need them in late winter. Conversely, bonemeal takes years to break down and is not available, he says. The better thing is to use a soluble or granular balanced feed and lay it around the bulbs as the tips emerge. This might be in January in a mild winter, so keep your eyes open. All that said, there are as many tips on bulb feeding as there are gardeners.
Good morning! I planted 3 PJM Rhododendrons this spring and have noticed that their leaves are turning red. Not brown, but red. Is this normal for this type of rhododendron? My other rhododendrons stay green all winter long. The soil doesn't seem to be dry. I've never had this type before, but I really like them and wouldn't want to lose them. Thanks for your help!
Adrian Higgins: This is one of the great benefits of this lovely rhododendron, fall color. Enjoy it. Make sure you water it thoroughly before the ground freezes. Folks, I am afraid we have run out of time. I'm sorry that I couldn't answer every question but please keep them coming in the weeks ahead. Gardening is a year round pleasure and hobby.
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