Adrian Higgins gave advice on tending your garden in the late winter

Feb 28, 2013

Washington Post gardening columnist Adrian Higgins takes questions on how to improve your garden in the late winter and early spring.

No question to ask but here you are here doing your first chat of the year and daylight saving time starts in 1 1/2 weeks so spring must be on its way! Somehow these winters seem longer and longer as I get older and older.

It's great to be back online, and spring is definitely in the air. I passed a lawn full of crocus tommasianus yesterday in full bloom. Love that harbinger. My threshold though is the sound of the dawn chorus, when the birds get a jump on the season. That means winter is over to me.

Here is a link to today's column about how and when to prune shrubs.

This winter, like last, has left my hellebores without much in the way of brown or ratty leaves. Should I cut away last year's leaves anyway or just the few ratty ones--leaving the rest be?

If folks don't know the hellebore or Lenten rose (Helleborus x hybridus), they should. It's such a valuable perennial, blooming now and for weeks, and one of the few beauties of dry shade. Carefully remove last year's leaves now, whether they are tatty or not, they form an outer circle around the new growth. Be careful not to cut the new growth or your hand. 

The grass seed I sowed in the late (probably too late) Fall hasn't produced any grass so far. Should I try to plant more seed? If so when? Otherwise, what can I do to avoid the current bare areas from turning back into the weed patches I hoped to eliminate a few months ago?

Grass seed should be sown between early September and late October. Your seed may have germinated and will spring up, but I would give the lawn an over seed now. Plan to renovate your lawn in early fall. 

Adrian - I love, love, love the classic Flowering Dogwood (Cornus florida). I have a bunch in different locations on my property that are slowly succumbing to what I presume is anthracnose. I'd like to replace them with more of the same but I realize that's probably not a good idea. Is there a resistant dogwood that looks (almost) exactly like C. florida? If so, can I plant near existing trees or is that a bad idea? One tree in particular is dead, but has evolved (devolved?) into a beautiful lichen cover trunk with many lichen covered branches. I like the look of it and so do the birds so I'm in no hurry to cut it down, but I'd like to get my replacement tree in the ground ASAP so when the dead one finally comes down, the new one will have some size to it. Is there anything else I need to be concerned with regarding replacing dying dogwoods? Thanks!

If you think they are declining from anthracnose (they may not be) you would want to make sure all the old foliage is removed from the area. Rutgers has released some anthracnose resistant hybrids. This disease is worse in cool, wet springs, and goes away once the summer arrives, so you should keep a check on foliage in April to June and remove infected leaves and stems then. I would still plant dogwoods. Most of them die, in my view, from poor care. They should be lovingly mulched with leafmold, kept free of physical damage, and watered sufficiently, deeply but not excessively during droughts and in their first two years in the garden. 

My wife has been nagging me to get the tomatoes started. I've always thought that early March was fine for starting tomatoes as they get too leggy and have to be transplanted twice instead of once before they go into the garden. My gardening buddy has already transplanted his tomatoes (his garden is part of a school project) and my wife thinks I'm behind the curve. When do you start your tomatoes?

I'm so glad you asked this question because the number one mistake people make in February and early March is to start seeds too early. Actually, the number one mistake is to buy seedlings and transplants that show up in mass merchandizers far too early. (This is my pet peeve.) I have started leeks, onions, cabbages and broccoli, and am about to start peppers. I would not start tomato seeds for another couple of weeks. Tomato transplants should not go out into the garden until early May at the earliest. Plan accordingly.

Adrian - I have a property with many large, old Tulip Poplars. I lost a couple recently and I can see the writing on the wall for the rest of them some I'm starting to thing about replacement trees. The property is in the foothills of the Blue Ridge in Fauquier county and is mostly fairly open lawn with 10 or so Poplars spread around it. What do you think would be an appropriate tree (or trees) for this area? I'm talking about a specimen tree that is native to the area. Thanks!

If you want a stand alone native tree for the ages, I would consider a white oak, an American basswood, an American beech, a sycamore, a yellowwood, a red (not sugar) maple, or a black gum. Other suggestions welcome, folks.

This is probably a strange question for you, but I have a hot tub that sits in essentially full sun, but gets late afternoon shade from the house. I'd like to put a shrub next to it. Do you have any suggestions? Ideally it would have 4 season interest, but I'd be happy with something that has pretty flowers at some point. Also, I'd like the maximum height to be 3 or 4 feet. Bonus points for a native, but I'd rather have something interesting to look at over a blah native. Thanks!!

Gosh, probably an itea,  Carolina allspice or Annabelle hydrangea. If you wanted beyond native, I would consider a Corylopsis spicata or a hybrid witch hazel.  They will get higher than that, though. 

In the article today it mentioned something about pruning knock out roses. Can you explain again about pruning roses and when is a good time to do it.

You want to prune roses now to reduce last year's thicket. Ideally, you should end up with an open framework of canes, that have been cut just above an outward facing bud. It's important to take out diseased and damaged canes, as well as suckers growing out of the ground from the root stock. Loppers or lopping shears are good to start on this because you get in to the prickly mess at arms length. You must have sturdy gloves for this job.

I forgot to prune my caryopteris last year so the flower display was pretty dismal. My question is about how to prune it. I understand it can take hard pruning, but the stems, clear down to the bottom of the plant, seem very brittle and they snap off easily. Is this a sign of something wrong with it, or do I just accept the snapping off as extra pruning?

This is a woody shrub or subshrub that benefits from a little grooming and trimming now. You can cut back some of the stems, but don't leave it looking like a hedgehog. Branches should have some green and pliability to them. 

We started a rather large garden last year. We're still trying to amend the dense clay soil. We've been tossing vegetable scraps, coffee grounds, and fireplace ashes on the area for the past year and we plan to rent a roto tiller this spring. Do you have any other recommendations? I wish we had more compost but it's difficult to create in a short amount of time. We could move to a raised bed system but I'd rather go more natural (the garden is 1000+ square feet and contains a couple fruit trees too)

I wouldn't try to do the whole lot in once go. You have to chop it up, physically and mentally. You can always sow a cover crop on any open ground, to keep the weeds back, while you work on smaller areas. Compost takes about six months to evolve, but you can work in leafmold now (half rotted leaves, many municipalities have piles for the taking). Main advice: Don't wait until spring to do this. Start right now. 

Last night I planted my basil and tomato seeds in our sunroom. Usually, I transplant the seedlings once the plants get a second set of leaves and put the seedlings in a larger pot. I put them in the ourdoor garden around the second week of May, depending on the weather. My question is whether transplaning the seedlings promotes deeper roots. Should I transplant the seedlings at all? Thanks for your help.

Yes, you should. I start seeds in soil blocks and get about 50 seedlings to a tray. About a month later, I pot them on with four inch pots, putting as many as four seedlings in each pot. You have to do this so that the transplants have a good root system when they go out. You also have to harden them off in April before planting. 

Would now be a good time?

Yes. I think this is a smooth hydrangea. Dig a generous rootball and do as little root disturbance as possible. Offer it a little mulch.

What is a good hardy shade tree for central Maryland? Sooner or later I need to replace the dying silver maple that shades my house from the summer sun.

Any of the species I mentioned for our friend in Virginia, though the basswood may be attacked by Japanese beetles.

Some of the other oaks might be worth a look: the black and chestnut oaks, for example. I think I might also plant the hackberry tree because it provides food for the glorious Mourning Cloak butterfly.  

Is it too soon to start looking for listings for community gardens, where a person can raise a small patch of vegetables? Will the "Post" run a list of them sometime in the near future, or is it too late to sign up already?

You can put your name on a list now, but it may be two or three years before you get a plot. At my community garden, there are 96 people on the list for probably 20 openings.  It is worth the wait, once you get one, your life will change for the better.  I don't think the Post lists gardens, I can check.  Maybe I should.

Leave the fireplace ash out of your soil & compost. A very little goes a very long way. I tried putting it in our compost, thinking the alkalinity would balance the acidity of the coffee grounds and tea leaves we have a lot of, but it just made sticky grey goop instead of crumbly black stuff. Our county landfill takes wood ash for recycling; you might try taking it there instead.

Thanks. I don't like to put woodash in the compost pile, I think it harms the microbial action. I sprinkle it over garden beds and the lawn before a forecasted rain. Makes your boots dusty.

After last summer's brutal heat, my lawn looked terrible. I seeded with a fescue blend in the fall, which helped, but want to put down more seed in the next month. Is there a type of seed you recommend that is more likely to survive the summer?

You can seed now to fill patches, but the best time is in the early fall so that the grass seed has developed a decent root system before the stress of the following summer. You have to buy turf type tall fescue by name. Get a blend of varieties developed for the upper south. 

Believe it or not, I've had the best luck starting tomato seeds outdoors(!) in my cold frame with the lid on (to protect a bit against cold nights). I wait till the end of March or early April to plant the seeds directly into the cold frame's soil. The seedlings aren't as tall as commercial seedlings, but they grow much sturdier stems, and get automatically hardened-off (when the lid's on full-time, it also helps control moisture). As the weather warms, I pull back the lid on the cold frame during the day (but close it at night), and by early-to-mid-May I've removed the lid entirely.

That is another good way to do it, if you are around to close the lid on cool nights.

Adrian, can you suggest a small tree for a front yard? We live near Annapolis where we have sandy, acidic soil.

I might try one of the smaller tree forms of crape myrtle (not Natchez), or I really like a new cherry tree introduction called Dream Catcher. If you want a native plant, perhaps a deciduous azalea or a mountain-laurel. 

Hi Adrian, We have such annoying deer! We caught them eating azaleas, which deer aren't supposed to like!! We've been in the house almost 3 years now, and it's always been in desperate need of landscaping. What plants do you suggest that would offer nice, nearly year-round blooming/greenery that the deer won't eat?

I think deer love azalea. Perhaps some boxwood and big lavenders. If you can, try to exclude them. Here's one source:

Do you have a favorite soil testing method? I have been looking at the variety of DIY kits vs sending to the extension folks...Hard to know which to do! Thanks

I think the  DIY kits are so unreliable as to be of little value. In a way, you don't need to get your soil tested, you can see for yourself whether it is in good heart. Dark, friable, organic, full of earthworms. Diggable. 

Planted a red clover cover crop on a new vegetable bed (Western Massachusetts). When should we dig it under? Our planting date is mid/late May.

You could cut it a month earlier and then dig it into the soil. Don't worry if it hasn't fully rotted by planting time. 

I just found a bag of tulip bulbs in my garage. I bought them last fall with every intention of planting them; is there anything I can do to salvage them? It's way way too late to get them in the ground, right? Thank you!

Sorry. Even if they haven't rotted, they need 11 weeks of chilling to set flower buds. If they are still sound, you could put them in the fridge I suppose until late May and then force them indoors. I wouldn't bother, myself. 

How old do classic dogwoods live to be? How can you tell if it's just reached its natural end, or if it's diseased?

Dogwoods decline by dieback of stems and branches. If you can remove dead twigs and branches as you see them, the tree will live longer. 

Higgins: "If you want a stand alone native tree for the ages, I would consider a white oak, an American basswood, an American beech, a sycamore, a yellowwood, a red (not sugar) maple, or a black gum. Other suggestions welcome, folks." If you're replacing 10 trees, pick all of Adrian's suggestions. Plant a variety instead of all of the same thing, to minimize problems from tree loss in the future.

Good idea, thank you. If you have the room. Many folks (including me) don't fully recognize how much spread a tree will achieve. 

We've all known the sort of insufferable person who LIVES for being the neighbor or co-worker or other acquaintance who gets the earliest ripe tomato in his or her garden. But in fact isn't this a fool's errand, because tomatoes originated nearer the Equator where days and nights are of fairly equal lengths, so are genetically evolved for not ripening till late summer?

Some early varieties (usually determinate) will fruit by mid to late July, but I view tomato season as late July into early September for us. There's no value in putting big tomato plants out in May, they will be checked by the cold soil. 

Should we give up and accept that our summers will be brutal from now on, and plant more southern-type grasses in our lawn? If so, what would you recommend? I am in Maryland, between Baltimore and DC.

No, because zoysia is horrible in my view and bermudagrass isn't much better.  Fescues work if you pick the right variety and are willing to renovate the lawn fairly regularly. 

Welcome back! I direct planted snow peas, spinach and kale in my garden this past weekend, and started broccoli/brussel sprout transplants indoors. Anything else I can start now? I was thinking of direct seeding green onions- it seems early but I've found that if you wait too late to plant cool-weather veggies they get scorched by early summer heat waves. Thanks!

Getting  a bit late for onion sowing, though you can buy sets. I would try sowing lettuce soon, and I have just sown my fava beans. 

For the love of god, will someone start a campaign to end the drastic pruning of crepe myrtles?!? It makes me physically ill.

I agree. If I wanted a hat stand in the garden, I would put a hat stand in the garden. Ok folks, we have to go. I'll be back on line March 21, first day of spring. Yay. 

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Adrian Higgins
Adrian Higgins is The Washington Post's gardening columnist. Read his recent story on gardening during a mild winter and follow him on Twitter.
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