The Garden Plot
Hosted by Adrian Higgins
Washington Post Garden Editor
Thursday, Sept. 7, 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.
What are good plants for boggy backyard areas? Our yard catches a lot of water coming off our neighbor's uphill property. I know that we will have to eventually put in some sort of drainage system but are there any plants, etc... that would be good for drying an area out?
Adrian Higgins: To name a few that come to mind: Bald cypress or dawn redwood, (big, deciduous conifers); river birches; myrica (large, evergreen shrubs); various kinds of willows; tupelo trees; the oak Quercus palustris; inkberry holly; red and yellow twigged dogwoods; and, among perennials, hardy hibiscus, Euphorbia palustris; ligularias.
I love this forum. Thanks!
Two questions...I have several hostas, one of which (Little Aurora) is turning yellow and brown and losing all its leaves. The hostas have been planted in the vicinity of a black walnut--and didn't seem to be having problems--but when this one started to decline, I moved it to a different, still shady, spot. That didn't arrest its decline, and now I'm wondering if it was just the normal end-of-season decline, and some hostas go through it earlier than others?
Also, I have lots of lavender planted on a sunny slope. The plants are 2 and 3 years old, and I probably haven't been as vigilant as I should be in trimming them back. Now, wanting to trim them back (I read no more than one-third of the plant), I see that where the branches have been swinging down with the angle of the slope, they're all greyish-brown underneath and yucky. If I cut off the newer, green-grey growth, will this grey-brown growth send out green shoots--or will I be killing them?
All of the top growth looks good--I just didn't realize how awful it looked underneath the mass of branches spreading out in all directions. Plus some is about to flower again, and I hate to cut that off--but should I just bite the bullet and trim back for the sake of checking new woody growth?
Adrian Higgins: I think the hosta is just going into its end of season malaise, especially if other plants have been unaffected by the walnut. You might want to do some light pruning of the lavender, but I would wait until next February and cut it back quite hard. You can do this as long as the plant is still dormant. The rains have sorely affected all gray leafed plants this year. Don't mulch lavender with bark, use sand or chicken grit instead. This will reflect light and burn the moisture off the leaves.
Grosse Pointe Park, MI:
FYI: Last week there was a question about transplanting peonies. According to David Turrant, the host of The Canadian Gardner, when moving peonies plant them at the same depth and orient them to the sun as they were originally. One can use a piece of string or crayon to mark the plant when moving it to a sunny, soil rich, spot. It worked for me this past spring, so there is no reason for a five year wait for peony blooms. If it isn't too late, give this a try.
Adrian Higgins: Good idea, and now is an excellent time to divide perennials.
When is the best time to plant rose bushes? My wife and I have set aside a garden plot at our new house with the intention of planting roses there but it looks barren. Can we plant rose bushes now or do we need to wait for spring to come around?
Adrian Higgins: Now would be a good time, but there are not generally available. The retail nurseries consider them a seasonal item and sell them in late winter, which is a good time to plant them also. Get their early, not just to select the variety you need but to get the roses in the ground before they break dormancy and grow like topsy. Since roses really respond to rich, deep soil, you could start excavating old soil and putting loads of organic matter in the future rose bed now, allowing it to break down into humus over the winter. Find a site with at least six hours of direct sunlight.
It's a little late in the season now, but for future reference--should you deadhead daylilies? Thanks.
Adrian Higgins: The flowers shrivel and fall off of their own accord. Fastidious growers do pluck off the waning blossoms to keep the show looking fresh, but that's not necessary. When all the buds have come and gone on a stalk, the stem dries out and after several weeks can be pulled off the plant.
Will my caladium (sp?) winter well or should it be potted and brought inside for the winter?
Adrian Higgins: Yes, pot it up and bring it indoors, or lift the bulb and store it in a ventilated box, setting it out again next spring.
Hi Mr. Higgins,
I inherited four pear trees when I bought my house this summer. They just became ripe this past week, and are very apple-like. Any idea what kind they are?
Also, could you suggest a few resources for buying ornamental grasses in the D.C. area?
Adrian Higgins: The most common pear in our area is the Bartlett. Like all European pears, you need to ripen it off the tree for a week or so after picking. Pick the fruit when the tapered base near the stem gives a little with thumb pressure (the bulk of the fruit will still feel hard) and then keep the pear in the crisper of the refrigerator to allow for gentle and steady ripening from the core outward.
I put some seeds from my impatiens in a pot of dirt last week and they are sprouting like crazy. Will they grow and bloom indoors this winter? Can I put them outside next spring?
Adrian Higgins: Yes, if they get enough light and are not allowed to dry out.
Would like to know what are the ingredients (easily available and not very expensive) to prepare a good soil for plants! What are the white particles in the potting soil I buy from the store! Would you recommend any special soil for planting Tulip and Daffodil!
Adrian Higgins: It depends on the size of the planting bed. If you are putting in just a few cherished perennials or small shrubs, I would take a bag of top soil, a bag of humus, and maybe some sphagnum peat moss and blend them for a light and open soil mix. If you are planted larger shrubs or trees, very little soil amendment is necessary as long as the existing soil is loosened sufficiently for the roots to grow into. The most common mistake is for people to dig a hole just fractionally larger than the rootball out of the pot: Far better to work the soil at least six and preferably 12 inches beyond the existing root zone. If you have large areas to prepare, I would stockpile leaves and lawn clippings and dig them in or hire a rototiller. Tulips and daffodils benefit from bulb food when planting. If you are setting your daffodil at, say, six inches deep, plunge the trowel or bulb planter down eight or nine inches and allow some of the loosened dirt to fill the bottom of the hole so that the roots will have open soil to grow into.
Is there any perennial over about 2' in height that is evergreen and can take some shade?
Adrian Higgins: A few, but you would broaden your choices if you included woody ground covers too. The perennials that come to mind: hellebores; euphorbias, evergreen ferns, and shade tolerant grasses.
I read with much interest Charlie Fenyvesi's article today on crape myrtle. Can you please tell me if they are deer-resistant? Many thanks!
Adrian Higgins: I believe they are if only because the blooms above seven feet are beyond the deer's reach. Select a tall tree form variety for this reason.
I like to plant fall pansies in my front
flower beds, but it gets SO expensive to
buy the bedding plants. Can I plant pansy
seeds instead? When would I do that?
Adrian Higgins: It is too late now, I suspect: Annuals need about six to eight weeks from seed to garden, including a period of hardening off--acclimation to the rigors of the outdoors. You could give it a try, though, and provide a landscape fabric over the young plants until they get established and during the coldest days of the winter. If you do that, your pansy display next Feb. - May will be spectacular.
My lawn is infected with that nasty oriental grass called Johnson's grass (what I was told). This stuff is as aggressive as bamboo and applying an herbicide and then digging up my entire lawn and reseeding last year didn't solve the problem. Do you have any advice on killing it?
Adrian Higgins: Check to see if any selective weedkillers are registered for Johnson grass, and if so apply this fall. In the late winter when it regrows, dig out the emerging grass, being careful to extract the root intact.
Is it time to plant bulbs for Spring and Summer flowers for next year?
Adrian Higgins: Plant daffodils as soon as they arrive, tulips other than early season varieties can go in as late as December. If you can find lilies for next season, they do better if planted in the fall than the more common period of early spring.
I have a couple of willows, a ornamental cherry, and a white pine which all need to be pruned. They've grown so much with all the rain they're shadowing the lawn and house too much. My question is, having never dealt with a tree service, how much should we expect to pay (ballpark) to prune? They are so large you'd have to either climb or use a cherry picker. Any help appreciated. thx.
Adrian Higgins: Weeping willows grow large (30 ft by 30 ft) and white pines even larger. (70 ft by 20 ft in time). If these are too large for the space, better to remove them now than spend thousands over the years trying to get them to conform to your available space. As for a tree service, find a reputable, established firm and get two or three different quotes, which can vary widely for mysterious reasons.
I've submitted this question before, with no luck getting a response. But I'll try again... I have a ficus plant indoors, which seems to go through varying stages of misery. First it developed lots of "nodule" things along it's branches, although didn't seem worse for it. Now, 1/2 the tree's leaves have dried & fallen off, & I'm worried the rest will soon follow. Are there particular ficus ailments I should be aware of? Thanks so much!
Adrian Higgins: If the leaves turn yellow before falling off, you are overwatering. If they are just dropping, the plant may be in too much darkness. Keep the plant moist and well fed until November and then let just water sparingly.
Hi Adrian! I am a novice gardener who would like to start this fall - but first I have to clear away four years of weeds and previous owners' plants that have have suffered neglect since I bought my house. What basic steps ("clearing," "enriching soil," "mulching"?) should I take to prepare the garden to plant bulbs in fall, and transplanted flowers in spring? And in what order? Thanks for your help!
Adrian Higgins: Remember that bare soil invites new weeds and soil erosion, so proceed methodically. First, remove obvious weedy and sick plants, but don't yank out everything. Some shrubs including evergreens can be revitalized by either cutting back hard or selective pruning.
Once you have weeded and cleaned up, buy some bags of humus or compost and work them into the soil. Then spread a three to four inch layer of mulch to keep back the winter weeds. You can spend the winter poring over catalogues and getting ideas for plantings in the early spring.
I had a pink dogwood planted late last August that appeared to have succumbed to the heat and sudden cold because it did nothing in spring. The tree is about 8 ft tall with no leaves or any signs of life. Just in the last 2 weeks I've seen a group of "suckers" springing up from the base of the tree. Can I hope for the entire tree to revive? Should I cut the top limbs off? My dad says it will take 10 years for it to get any size so I should pull it out and start again.
Adrian Higgins: I think if the entire top growth is dead, I would remove the tree entirely and select another species, maybe an upright Japanese maple or redbud. The suckers will likely succumb to fungal blights next year and even if they survive, you will never recover the natural form of the tree.
I want to move around some perennial plants in the garden this fall. I have a huge Sedum--Autumn Joy that I'd like to move and split in two this month, but as you know it is blooming now. Will it harm the plant if I do this in the fall rather than Spring? Would it be better to wait until the blooms fade?
Adrian Higgins: Either wait until the blooms fade or remove the spent top growth this winter and lift and divide in early spring when you see the new season's growth.
Great article today on vegetable soybeans. I thought I'd add a bit of a testimonial. I've grown the butterbean variety from Johnny's Select Seeds for two years in a row now in my home vegetable garden and it's at the top of my seed list for next year as well. They thrived in last year's drought. They thrived in this year's deluge. The vines are incredibly prolific and relatively pest free. Japanese beetles do like them, but they're easily picked off and some damage to the leaves apparently does nothing to deter production. As compared to other shell beans, particularly limas, they're easier to grow, take up less space, mature more quickly and consistently, and, frankly, taste better. The peak harvest occurs in early to mid August when planted in late May here. Thus, alas, my butterbeans are gone for this year. I didn't even get a chance to freeze any as they were just too good fresh. Vegetable soybeans are really a worthwhile crop for the homegardener.
Adrian Higgins: Thanks for the information.
Chevy Chase, MD:
Hi - what can you tell me about lilies of the valley? I wanted to plant some at the base of the fence that surrounds my yard. Do they do well in partly shady conditions? And how are they sold, bulbs or seeds? Thanks.
Adrian Higgins: They are sold either as bulbs or pips (tiny things), which can be planted anytime, or as seedlings, planted in early spring. They do well in partly shaded conditions. Their foliage tends to get ragged by mid season, especially in dry years, but their spring blooms and fragrance are heavenly.
For the person in Gaithersburg who wants to hire a tree expert to prune trees:
I used an arborist (a member of the Intl Society of Arborists) to oversee the pruning of my branch-dropping Silver Maple. Cost was about $1,000, so if you use an arborist, you're prob. looking at $1-2k. I chose a member of the ISA b/c they are required to meet certain educational & insurance requirements. I figured paying extra for a certified tree expert would save $ in the long run.
Adrian Higgins: Thanks, passing it along.
I have a mature green-leaved Japanese Maple in front of my house. I believe that the tree could benefit from some pruning and shaping. Is fall a good time to do this, and do you have any recommendations on how much pruning this type of tree can handle? Thanks.
Adrian Higgins: Pruning maples can be akin to a Zen like experience. You are sculpting the plant by taking away. (I'm assuming you're referring to a weeping form) But you must know what you are doing. It is difficult to convey the desired cuts in text alone and I wouldn't do it anyway until the plant is fully dormant in winter. Not only because that avoids stress and frost damage but because the absence of leaves helps you see the form better. I would recommend "the Pruning Book" by Lee Reich (Taunton, 1997).
I will be cleaning the rose beds soon. My roses suffered terribly from black spot this year because of so much rain despite regular sprayings of Funginex. What should I do with the pine bark nuggets that I have used as mulch in the rose beds? Can I put it in other beds? Can it be used again in the roses? What kind of mulch or protection do you recommend for roses in winter?
Adrian Higgins: In Washington D.C. a gentle mound of mulch will be sufficient. Wash it away in March, using a garden hose. The key to beating black spot is sanitary gardening. You mulch is probably full of spores, you may want to rake it out and replace it with fresh mulch this fall. Fungi can develop resistance to repeated applications of one fungicide, so next year select a different type, even organic copper spray. It is essential though to use it as a preventative. Spray in late April before the disease appears, and then only repeat if blackspot returns.
Boggy in Annandale:
Thank you so much for the advice! Another question: In one of my particularly wet areas, I have a filbert tree. Is there any advantage to having it there? It is very ugly and grows uncontrollably so I am thinking of getting rid of it.
Adrian Higgins: If it is irredeemable by corrective pruning, and you don't like it, get rid of it. Cutting down an ugly plant is good for one's mental health. On that note, my time has come to a close, thanks for all your questions today. I'm sorry I couldn't answer them all.
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