Washington Post Gardening Columnist
Thursday, May 20, 2010; 12:00 PM
Washington Post gardening columnist Adrian Higgins was on line Thursday, May 20, at Noon ET to talk about succulents and their ease of use in containers.
Germantown, Md.: Seeking Sungold tomatoes. I usually grow these candy-sweet cherry tomatoes from seed purchased from Thompson & Morgan, but nothing germinated this year. Where might I find Sungold plants? I have seen the plants for sale only once -- several years ago at the annual herb/vegetable sale at Lewis Ginter Botanical Gardens in Richmond. I've made numerous stops at the nurseries and garden centers in up-county from Comus to Olney.
Adrian Higgins: It's still not too late to start these from seed. They will quickly catch up as the soil has warmed. I would get a packet either from a local garden center or mail order and sow half of them in a nine inch pot, kept in a bright but sheltered spot, perhaps netted for a week against the squirrels. Don't worry about thinning the seedlings. Just plant them once they show their true leaves and bulk up a bit.
Arlington, VA: Hi. Thanks for taking my question. I know absolutely nothing about gardening, but I really would like to start taking an interest. How would you suggest a complete newbie get started?
Adrian Higgins: The best way to learn is to do it, but under the guidance of an experienced garden. I would either volunteer at a local public garden or try and inveigle your way into sharing a community plot with someone.
Falls Church, Va.: Hello! I'm growing parsley from seed for the first time. I have about 15 little parsley plants sharing three 10-inch-tall pots right now. The plants are about 6" tall and get partial sun. I read that parsley has a long taproot, so I want to re-pot them into their own containers--to get a robust plant, how deep a pot should I use? Also, should I transfer them into a spot so they can get full sun? Thanks!
Adrian Higgins: Parsley doesn't like our hot summers, so I would put the seedlings in a bed that gets some afternoon shade. I would start fresh seed in July for a fall and winter crop. Next January, start parsley indoors and then set out the transplants in mid to late March, weather permitting. As long as you are careful, you can pot it on without damaging the roots unduly, but this is always best done on a shady day, and then keep them in a shady, sheltered spot until they get over the transplant shock.
Germantown, Md.: Why does my basil keep dying? I have always started basil from seed in my basement, but a new, better insulated heating system cooled the room so much that nothing germinated, so I was forced to buy plants. I have now made three rounds of purchases, but most of the seedlings just wilted and died and what hasn't died is not thriving. The edges of the leaves are browned and curled. None of the stock in nurseries and garden centers looks that great either. My Italian parsley is also suffering from "failure to thrive." Is there some disease affecting basil this year? Has it just been too cool and damp?
Adrian Higgins: I'm hearing reports of diseased stock this year. Are other people having problems with their basil plants?
Fairfax, Va.: I have long been a fan of unusual succulents as office decor. The problem I have is that I can never seem to get them to thrive. I have tried to follow the standard advice of not watering too often (I saturate them once a month year round) and I keep them in as bright of a location as I can, but they still often start to die off. Are there any specific tricks of techniques that might increase my success with them here in my cubicle?
Adrian Higgins: I have to believe they are simply not getting enough light. What may seem bright indoors is actually downright murky in terms of foot candles or whatever the measurement is. Foot candle sounds like little tapers pushed between the toes. Probably not recommended.
College Park, Md.: I would love to expand my succulent collection but I am having a hard time finding different varieties. Where can I purchase some of the less traditional ones?
Adrian Higgins: The good news is that because this is becoming popular, more agaves, echeverias, aloes and sedums are finding their way into popular consumer streams. If you look up Proven Winners, you will find quite a broad range and links to retail outlets. Probably the best thing to do is also to call local independent garden centers, or visit them. I did look at their websites but they are woefully incomplete.
Bethesda: Adrian - our day lilies are out of control - absolutely everywhere, dense, and taken over an area. They are about to bloom. Can I do some selective dividing now or do I need to wait until fall? I can move some to our backyard - need something with roots for erosion control, and the speed these things spread, seems like they would be good for that.
Adrian Higgins: I would wait until late summer. You can dig whole clumps with a garden fork, and separate them by hand. I cut back the foliage and soak the tubers etc. in a bleach solution overnight, and then replant them as needed. This ensures clean stock.
washingtonpost.com: Hi, all chatters, Share your garden photos with Adrian Higgins and Local Living.
Adrian Higgins: Especially roses, this is a banner year for roses, so do share your pictures and identify the varieties.
Maryland: I would like to move from my present practice of gardening (sticking a plant in the ground and hoping for the best)to being more knowledgeable and was wondering what beginning gardening books you would recommend for me?
Adrian Higgins: It all starts with the soil, and books can only convey so much. The secret is to provide good soil, and select your plants according to their sun/shade and watering needs. One of the biggest mistakes is not accounting for future growth and spacing them too tightly. Books? Gardening is so multi faceted that I'm not sure there is one book to recommend. Reader's Digest actually has a good all round book on gardening. And the American Horticultural Society has lent its name to some useful tomes.
Washington, D.C.: A non-succulent but timely question: how can I remove ants from peonies when I cut them from the garden to bring into the house? Thank you.
Adrian Higgins: I would just wash them off. They are harmless and drawn to the sticky secretions on the buds.
Coastal Massachusetts: A treat to have you online! Slightly off-topic question. Can you recommend a Zone 5 groundcover succulent by name (cultivar) that would work well with an all-blue/purple hydrangea-and-foliage-shrub border? I water the shrubs in the summer, so it's not bone-dry. Soil is rather poor, though. I need something to keep weeds down and set off the deep blues. Is there a pale green or chartreuse succulent 3-10" tall that you particularly like?
Adrian Higgins: Sounds like Sedum Angelina is made for that need. Creeping jenny would work, but is not a succulent and would like it moist.
Anacostia: Could I bring up an earlier issue? The heavy snows created top damage on our 2-foot boxwoods. The tops started to spread creating holes in the center. My partner said that one of your articles said to wire them to encourage the boxwoods to close up again. Will wiring actually close them up or could the wires just create more damage considering the sort of fragile branches of the boxwoods?
Adrian Higgins: What I did years ago, was a piece on netting boxwood preventatively to prevent snow splaying. After the damage, however, it's a question of pruning out broken branches and being prepared to wait for the resulting new growth to turn woody, which takes several years.
Laurel, Md.: Behnke Nurseries in Beltsville has a good selection of succulents right now. The only problem is that their supplier doesn't label the varieties for houseplants, so only a few of them are labeled with names. But they have succulents in all colors and sizes.
Adrian Higgins: Thanks for the information.
Rockville: Hello - when should lilacs be pruned? Thanks!
Adrian Higgins: Now, or earlier, to prevent the plant putting energy into seed set. Also, removing the oldest stems will rejuvenate the plant and diminish problems with a pest called lilac borer.
Cactus Show & Sale: Hi Adrian,
Thanks so much for the great articles about growing succulents. I was hoping you could help spread the word: the National Capital Cactus & Succulent Society is holding a free show & sale this Saturday:
Meadowlark Botanic Gardens Located in Fairfax County, Virginia between Route 7 and Route 123, off of Beulah Road Saturday May 22, 2010 10:00am - 5:00pm
There will be some great plants on display and many for sale, including plants that are winter-hardy in the DC area.
Adrian Higgins: Yes, everyone should go to this show. It will be fabulous and I'm sure succulents will be for sale.
Bethesda, Md.: Hello Adrian! My husband almost done digging out the last bits of stump from an ancient and far too big magnolia tree in our semi-shady front yard. Hoping now to find an interesting but very small tree to take its place. One of the small Japanese maples might do, but we'd like other options to consider. Any suggestions?
Adrian Higgins: Lots of great, upright acer varieties to pick from. I would also consider the native magnolia, Magnolia virginia and my new most favorite large shrub magnolia, M. sieboldii.
Silver Spring, Md.: When is the best time to cut back hydrangea without jeopardizing next year's blooms? Also, is there a rule of thumb as far as how severe the "haircut" should be? Ours haven't been pruned in years and they're a bit out of control.
Adrian Higgins: Not now is the answer. They're setting bud. Hydrangeas should not be cut back hard in spring, which is the mistake a lot of people make. You can groom the plant by removing dead canes once spring growth is evident (and past the last frost). Otherwise, leave it alone. If a bush is really congested, you can take out some of the older canes entirely. This can be done at any time really.
Bishop weed as ground cover?: We have a euonymus hedge with a redbud at one end and a sweetgum at the other, and are having trouble keeping the bed weeded. Would we be able to keep bishop-weed, goutweed -- you now, that pretty low-growing pale green and white stuff -- out of the yard if we underplanted the hedge and trees with it?
Adrian Higgins: This is a truly invasive plant. I wouldn't go with that. I would weed the bed, lay mulch, and then plant perennial ground covers through the mulch, things like epimediums, hostas and coral bells.
Silver Spring, Md.: I loved your column today and am so thrilled that you're chatting again. Can we please have the garden chats back??Question on the succulents. A good friend gave me a container filled with plugs of sedum about a year ago. They are doing marvelously and filling out and spilling over. I was wondering--since they seem to root so easily and spread--if i could just clip some of the pieces that spill over and tuck them into the ground. Would they root fairly easily? What do you think?
Adrian Higgins: How lucky to have such a friend. Yes, you can pinch them out and set them in the ground and they should root happily. But, don't just put them in mulched, clay soil, they will need the same free draining gravel/compost mix of their mother plants.
Day lilies suggestion: Wait - bleach solution? A living plant? Is this for storage or immediate replanting? I'm a little lost on the suggestion.
Adrian Higgins: Your divisions will have roots, tubers, crowns and some leaves. They can and should soak in a bucket of 10 percent bleach solution for a few hours before planting. This will hydrate them and kill thrips and diseases. Wear rubber gloves.
Garden Pests: This is a little off-topic, but do you have any suggestions for keeping snakes out of the garden? I have heard everything from mothballs to marigolds suggested, and would appreciate your opinion. (Yes, I know snakes keep away unwanted insects, yes I know they are shy and non-poisonous, but I am terrified of them to the point that I have stopped weeding certain beds!)
Adrian Higgins: What sort of snakes, do you know? They will eat insects and small mammals.
Columbia, Md.: I would like to have succulents in containers by my front door year-round. You say that one needs "to use a container that is frost-proof." Would you elaborate? Also, what is "never die" (a succulent my in- laws grew in pots outdoors in Philadelphia for decades)?
Adrian Higgins: I suspect that was a variety of Sempervivum, which is Latin for ever living. Concrete would work, so would Fiberglas or metal, though the latter gets hot.
Washington, D.C.: Adrian! It's so good to see you back in the lineup! I have a rhubarb question. After reading a few of your comments about growing rhubarb in the DC area, I got my boyfriend's mother to give me some sections from her garden and planted them two falls ago. They've come back each spring, and look pretty good this year. I'm reluctant to harvest any yet, though, because I want them to really settle in. He visited her last weekend, and I asked him to bring me back some cuttings - I meant just some stalks so that I could cook with them, but he misunderstood, and brought back a bunch with roots attached. Is there anything I can do to plant them now and get them through the summer? Or should I just cook with the stalks and forget about planting them. It seems like a waste, but if they're not likely to make it anyway, I want rhubarb cake!
Adrian Higgins: I would think your clump is established and you could harvest some stalks. The leaves are toxic. As for the new divisions, see if they will grow. I would give them a little shade and enriched soil. I think I killed mine by overwatering them. They are better divided in the early fall.
Basil: Instead of buying the plants in pots at the nursery, last year we tried going to Safeway and buying our basil in the herb section - it still has roots on it in the little plastic packaging and there were 4 or 5 stems that were a good 6" long with lots of leaves per stem. We planted those in pots and they've done remarkably well. We are still using the one we planted last year as we were able to move it indoors for the winter!
Adrian Higgins: Thanks for the tip.
Vegetables in shade?: Are there any vegetables that grow well in shade? The trees in our yard have grown in the past few years and what used to be a lovely sunny spot is getting more and more shaded. We are expanding the garden and trimming back the trees a bit, but there will still be a portion that is more shaded than sunny. It will still get some early morning sun.
Adrian Higgins: The short answer is, not really. I'm going through this problem myself and have moved my veggie garden to a sunnier spot. You could try some salad greens and carrots. I am putting in currant bushes in my old garden, in the theory that they will enjoy some relief from the heat.
Basil plants: What my wife and I have been doing the past few years is just transplanting the basil plants that we buy from the veggie section at Whole Foods.
We pick most of the leaves for a meal, leave a few and put it in our herb garden.
It has worked wonderfully for years.
Adrian Higgins: There you go.
Seattle, Wash. Last July the house next door burnt down causing some damage to our trees. Our apple tree this year (top was singed and we lost all of our apples) has not bloomed although it leafed out beautifully except for the very top of the branches where it was singed. Could this just be a dormant year or could it have been permanently damaged? We've only had the tree for two years now.
Adrian Higgins: It will take two or three years to reach bearing age. Be patient. Do prune out wayward branches as they grow.
Silver Spring, Md.: I'm very interested in climbers this year after having built new trellis-style fencing around my property. Any recommendations on fabulous climbers? Do you have any particular favorite clematis varieties?
Adrian Higgins: There are lots of great clematis to pick. I would stay away from the large flowered hybrids, which are prone to wilt. Any of the viticella varieties are fabulous, and I have just planted clematis x durandii, which has lovely indigo-blue flowers.
Centreville, Va.: I'm looking for a perennial that will drape nicely over a retaining wall. The area gets shade in the morning and sun in the afternoon. Any suggestions? Flowering would be nice, isn't necessary. Thank you!
Adrian Higgins: This is a hot dry site, and I'm drawing a blank for perennials. If you're into pruning to keep things in bounds, I would go with winter jasmine.
Leggy seedlings: First time seed gardener! I started sunflowers from seed; they were probably ready to plant a week and a half ago but life got in the way so I'm only hardening them off this week. Plan to plant them on Sunday. Since they've been indoors for a while, their stems have grown a little crookedly -- one even takes a 90-degree zigzag out of the dirt (but the top part with the true leaves is growing straight up). Should I plant it extra deep to put the crooked part of the stem under the soil? Or will the stem correct itself once it's in the ground? (Assuming it even has a chance at this point ...)
Adrian Higgins: Don't bury the stem unduly, it will grow into the light, and straighten up.
Transplanted viburnum: I had a yard crew move a double-file viburnum about five and a half feet tall to a more distant spot in my yard (it had been planted too close to the A/C unit) and didn't notice until a few days later that they had not watered it at all. I've been giving it a deep watering every four or five days, but some of the leaves are still showing signs of root shock, although about half the leaves still look healthy. Do you think it will live? I know not to fertilize a plant in distress, but is there anything else I can do?
Adrian Higgins: I would give it a mulch of compost and keep the soil somewhat moist but not wet. Be patient. There may be some dieback, but with new growth next spring.
Alexandria, Va.: Hello!
I am very interested in this topic. We are planning to use potted containers to add color and plant life to our back patio area. I am particularly interested in succulents that would last through the winter, outdoors in the pots. Do you have any suggestions? Also, are there varieties that add height to a pot?
Adrian Higgins: You do limit yourself if you only use hardy succulents, but can still have a great display with stonecrops (sedums), iceplant (delosperma) and plants called orostachys and jovibarbas.
Aloe outdoors: Thanks for taking my question. Last year I put my large potted aloe vera out in the sun on the deck, after two days the leaves were dying. How much sun can they tolerate?
Adrian Higgins: You have to transition plants from indoors to out. And some aloes are sensitive to full sunlight.
Sleepy Hollow: The basil plants I received from a herb jar class at the National Arboretum are indeed turning yellow and just...lingering. There's one in a pot that's doing okay, but still slowly getting yellowish and brown leaves. I have kept them moist and they get good sun. The thyme and rosemary are flourishing though.
Adrian Higgins: Thank you.
Fairfax, Va.: Good Afternoon Mr. Higgins--I loved your article on succulents, but have an unrelated question. I have two 52-year-old sycamore trees that have some kind of fungal disease (our street is lined with them and they are all suffering). Is this something you are familiar with and do you have any suggestions as to care or cures? Thank you!
Adrian Higgins: Sycamores draw sap sucking pests that secrete honeydew that in turn gets a dark fungus called sooty mold. In such cases, a release of ladybird beetles would be a good bet. There's little else you can do about it, though some years are better than others.
Alexandria, Va.: I have one chive plant and one thyme that are easily 4 years old that have recently sprouted flowers (gone to seed?)-- are they salvageable or should I pitch them? I had hacked the chive back but the purple blooms continue. Thanks for your help and have a great day!
Adrian Higgins: Both chive and thyme flowers are some of the most attractive blooms in the herb garden. And chive flowers can be added to salads and other dishes, though not the whole flower, just a floret or two.
Henderson, Nev.: I recently moved to Henderson Nevada and the soil is like sand and gravel. I am learning to grow succulents in pots and I was thrilled when many of them got blossoms. My question is I am not sure as to how much water to give them. We have a very cold winter here as low as 39 and in the summer 115. Do you have any suggestions?
Adrian Higgins: I'm sure there are some succulents that would find the summer heat too much, and would need to be grown in the shade. A California writer, Debra Baldwin, has just written a book on succulents in containers (Timber Press) and I'm sure that would provide useful advice for such a hot dry climate. Anyway, we are out of time, and I'm sorry we couldn't get to all the questions. See you here anon.
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