Adrian Higgins on how to make the winter season productive and pleasurable, and all things gardening

By Adrian Higgins/The Washington Post
Nov 21, 2019

Washington Post gardening columnist Adrian Higgins took questions on gardening.

Hello Mr. Higgins, Very motivated by your article on continued "off-season" garden activities. Anticipating that we will have some relatively mild days remaining, is it advisable at this point to apply a pre-emergent to ornamental (flowers, shrubbery) beds? I did apply Preen Garden Weed preventer (not lawn weed preventer ) in early September, but I'm guessing that it's no longer effective for future germination at this point. I would like to minimize the broadleaf winter annual weeds that will begin to appear in late Feb/early Mar. Or is it too late for the current winter weed growth cycle?

Greetings all. The premise of my winter story is that there are loads of mild days between now and the next growing season to get on top of loads of tasks outside the frenzied demands spring and summer. I didn't address winter weeds. Preen is a product that prevents seed germination, which is linked to soil temperatures, moisture and soil disturbance. I don't use it because I do a lot of seeding of desirable plants and prefer to hoe out weeds. There are many winter weeds that are germinating now and may already have done so, beyond the power of a pre-emergent herbicide. Weeding beds between now and the end of the year will save a lot of woe later in the winter and early spring. 

Hi, all. Producer here with a link to Adrian's most recent column, a guide to gardening tasks that can help you make the most of the winter season.

I received a clump pf cannas from my neighbor and they did gloriously this year. In Indiana we would have had to dig them (probably before now) but we are new southerners. We have cut the plant down after the foliage was damaged by an overnight frost. What do we do to keep our cannas healthy and blooming?

Cannas use to be reliably killed if left in the ground, the same for dahlias, but now we have winters in which they may survive, though there are no guarantees. To be sure, you should lift the bulbs and store them in a cool dry place until next May. 

I'm a newbie in terms of growing plants. Can you suggest a couple of indoor plants that would be good to start out with? They need to be able to tolerate low or indirect light, and ideally they would be cat-friendly. Thanks!

I think pothos is pretty bullet proof in dark conditions along with Chinese Evergreen and aspidistra. 

Is it already too late to do things like overseed my lawn and plant tulip/daffodil bulbs? I'm in the D.C. area.

Sowing lawn seed is like painting, the laying of the seed is 20 percent of the work, the remainder is in preparation. I think it's too late for this year. You have plenty of time still to put in daffodils and tulips, until the end of the year, but the longer you wait the greater the risk of the ground freezing. Now is also a great time to find discounts on spring bulbs, but make sure they are not desiccated at this point if buying from a store. 

If I buy a Christmas tree the weekend after Thanksgiving, will it be a dry, needle-shedding mess by Christmas? Is there a particular type of tree that lasts longer, or is it all about proper tree care?

It's all about the care. A neglected tree will dry out in a couple of weeks, a nurtured one will stay fresh for a month or more. I recommend waiting until you have the tree home before removing an inch or two from the bottom. After that point, the wound must never not be submerged in water. The tree will take up a lot of water initially, so I like to place it in a large bucket after cutting and keep it outdoors in the cold for a few days so that it is fully hydrated once you bring it inside. Then it is essential to check it daily to make sure the tree stand's reservoir never runs dry. 

I bought a gooseneck gourd from a farmer's market and it's still sitting on my front porch. I'd like to harvest the seeds and plant them next spring. Should I keep the seeds in the freezer during the winter?

The chances are pretty good that the seed of this variety will grow true, this isn't a given. Scoop out the seeds -- don't wash them -- and let them dry on a sheet of paper for a few days - turn them. Then they can be stored in the freezer or the fridge. The fridge is sufficient. In warmer regions, the seed is sown directly in the growing bed once the soil has warmed, no earlier than mid-May. In colder regions with shorter growing seasons, it's better to start it in pots indoors a month before setting out. 

I've had gardens, some really large (2 acres and more) for many years. First garden was 64 years ago. I live in Iowa now. I have a small backyard so I had 6 tomato plants in 4 cages - Early Girls. Early on I noticed for the first time that deer were eating the plants. Then, about 2 weeks before they would be ripe, all the green tomatoes disappeared. I'm fairly certain that they were eaten by the deer. I've NEVER had deer eat tomatoes before. I had upwards of 100 tomato plants on a 30 acre farmette in Stafford County, deer central. Never had even one bite off any tomatoes. Are Iowa deer different? Clearly there are all sorts of better tasting stuff in my neighborhood (hostas, etc.). What do you think?

Deer eat tomato vines, and the fruit on them. I've seen this firsthand. The only remedy is to screen them out with netting/fencing.  

My husband took an electric hedge trimmer to the yew bushes that line our front walk without first reading up on how or when they should be pruned. As a result, there is now an enormous bare, branch-only patch where there is no needle growth whatsoever. Is there any way to remedy this (it's been more than a year) or do I need to have the hedge replaced?

Yew will regenerate from bare wood, in theory, but old leggy specimens seem loath to do so in our warm climate. If you are not seeing new growth by late spring, I would consider replacing it.    

Unlike, say, the weather of 20 years ago, my part of the country in the Florida Panhandle isn’t experiencing anything wintry. Although days have cooled off, nights have stayed well above freezing. My ginger garden hasn’t senesced; normally they would be dying back by now but the ‘Disney’ gingers are standing tall. Pentas continue blooming profusely—food for the honeybees and wasps that are still coming around. Even troublesome tropicals like gloriosa lily keep sprouting, and every couple of days I have to grub them out. A Gulf fritillary took me by surprise yesterday when it fluttered by to visit the pentas. There’s some raking to do, but mostly I am keeping things going as if this is extended summer, especially keeping container plants watered and spent flowers dead-headed. Looking forward to cooler nighttime temperatures!

Thank you for the report from Florida. I have seen the growing season here in the Mid-Atlantic extend markedly over the years, especially at its conclusion. November is the new October. 

My nandina grows like crazy - not spreading, just taller and taller each day. But i dont get many berries. It is in a sunny spot. Too much sun?

Nandina is a workhorse shrub and should fruit freely even in hot sunny conditions. Most berry loss is down to pruning in late spring when the flower clusters emerge. Plants also get leggy over time -- yours seem to be vigorous -- and you can restore bushiness by cutting back hard in late winter, this will encourage basal shoot growth and a thicker habit. 

Help! I’m overwhelmed with all types of pests in my vegetable garden. Squash bugs and cucumber bugs are the most troublesome. Is there anything I can do now to help my vegetable plants survive next season?

The eggs of these pests overwinter on vegetation, so it is important to clean up and bag -- not compost -- cucumber vines that may be lingering plant. If this is a persistent problem, you can try growing cucumber vines later in the season, or skip growing them for a year or two. Another option is to grow them under light, summer row covers that will exclude them. 

Hi Adrian! I recently bought my first house. It has a much-neglected backyard that had a pool in it (since removed), with the most compact soil I've ever seen. I gave up early on traditional grass, and let the clover take over- turned out to be a smart decision, as I don't think I'd have got much more than a bare spot otherwise. I'd like to put some raised beds for gardening. How should I design the beds to prevent drainage issues? And second issue- is there a way to scrape off what little topsoil there is and move it to another portion of the backyard? It won't be like cutting sod, but I'd hate to lose what little soil I already have back there.

Raised beds are a great way to provide instant drainage and soil improvement. I use planks set on edge. A couple of considerations -- if the beds are in areas that are waterlogged, they may not themselves drain sufficiently. If they are too high, they will dry out constantly and you may have issues with water flooding to other areas. 

As for moving good soil around, I wouldn't. You need to begin a multi-year effort to rebuild your soil and the best start is to chew up all those lovely leaves that are now falling and return them to your beds and even your lawn, so that they can break down over the winter, draw earthworms, and generally start to bring life back into the soil. If you do this consistently, adding compost as well, the soil will be restored in three to five years. 

I'd never heard of this variety before, but this heirloom variety thrived in our vegetable garden this season. They have all the virtues of other plum tomatoes, but being so much larger, are easier to process into sauce, etc. Are there any drawbacks we don't know about? (Other than being too fragile for commercial shipping, which is obviously of no concern to the home gardener).

This is one of the larger plum tomatoes, an heirloom variety from Poland. It is shy in seed production, but probably worth saving the seeds if you can find them. I haven't grown it myself, maybe others can speak to its performance in the Mid-Atantic. 

I put in elephant ears for the first time this past summer - such a dramatic, beautiful addition to the garden! I cut the foliage and dug up the tubers after the first hard freeze and have stored them in a mix of peat and potting soil in the garage. Is that the right approach to getting them through winter? I would love to have them back in the garden next year and also to avoid the expense of buying new ones!

They are happy to keep as bulbs over the winter, just as you have described, except I wouldn't keep them in soil. Better to have them in some inert material such as perlite. I like to hang them upside down for a few days before storing so that moisture in the hollow stems will bleed out and the bulbs can harden up a bit.  They should be kept in a cool, dry area. Check them periodically for rotting. They also produce lots of pups, which I like to separate before planting rather than now. 

Won't using row covers to exclude squash bugs also exclude pollinators and prevent fruit set?

Yes, that's a good point. When they are flowering, you should lift the row cover, preferably when you are there to make sure no bugs appear. Alternatively, you could use a paint brush to do the pollination yourself. 

I want to put a pair of potted plants on either side of my front porch -- what would you recommend? Bonus points if they're easy to care for and/or festive-looking!

The question is do you want hardy plants year round, or seasonal ones for the growing season. If the containers are to stay out now, they must be freeze-proof. I have seen very effective container plantings of the hellebore Pink Frost, which bloom in March. Camellias, especially dwarf varieties, are another hardy plant option with off-season ornament. Container grown plants are inherently less low maintenance than those in the ground, because they need watering and feeding more, and attention to such things as root pruning every couple of years or so. Year round containers also mean you have to plant hardier things, e.g. a plant hardy to Zone 6 in Washington rather than Zone 7 because of a lack of soil insulation. Generally, the larger the pot, the less the stress on the plant (but not the gardener's back).

Echoing Adrian's advice. We had a hard clay soil that I wanted to convert to a perennial bed. Initially the soil was so hard you could barely get the shovel in. Every year we added shredded leaves. Every new plant got compost in the hole. This year, as I was dividing perennials and the spade went in like butter I realized--it worked. Slowly and surely, it worked.

Thank you. Thank you.  

In today's column you make reference to outdated, boring groundcovers English ivy, pachsandra,liriope and vinca. Can you perhaps suggest some more current and less boring ground covers that we might use come early spring? Thanks.

I like such things as heucheras, foam flowers, ferns, hostas, sedges, grasses, leadwort, epimediums, to name a few. 

I have nandina and rhododendron in the same bed in front of my porch. The nandina is very scraggly, and the rhododendron is huge and a bit out of control. What is the best way to prune back both to get something that looks a little less unkempt, and when to do it?

Do cut back the nandina rather hard. The rhododendron is a more sensitive beast and anything you do now will remove flowers next spring. I would selectively remove or shorten a few branches, but in a way that keeps its natural outline. No stubs. We've run out of time, but thank you and see you here again in a few weeks. 

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Adrian Higgins
Adrian Higgins is The Washington Post's gardening columnist. Read his latest columns and stories here and follow him on Twitter.
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