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Posted at 10:20 AM ET, 02/02/2012

Our gardens in a mild winter: the good, bad and beautiful

Winter gardening tips from a horticultural meteorologist...

As everyone in metro region will attest to, it’s been warm, very warm. So what does it mean for our gardens? Is the warmth good news or will gardens face a rude awakening if groundhog Punxsutawney Phil is right and 6 more weeks of winter await us? And, is there anything we can do about it?

Temperature departure over last two weeks in mid-Atlantic (Great Plains Regional Climate Center)
Let’s begin by checking out the temperature departures from average over the last two weeks. Most of the region was averaging a whopping 6 degrees above normal for that period. These temperatures are more on par with early March than the “heart” of winter.

I’ll say right off the bat, my garden does not look much different this year than any other year, except it isn’t buried under a snow drift (for me, this warm weather makes gardening a walk in the park compared to cold/snow of the last two years)! For example, my oakleaf hydrangea do not yet look like what they will in early March, full of buds and ready for spring. Why is that? Many of our plants evolved over the centuries to be more in tune with the dependable daylight hours than the more erratic temperature regime.

Keep reading for my tips on readying your winter garden...

Are you seeing abnormal blooms around the region? Call me skeptic, but I haven’t seen anything too out of the ordinary downtown. Having said that, here are some thoughts about what good or bad things may be happening to your lawn and garden in this warm weather...

Is blooming now really bad? It depends...

Shrubs like winter hazel, winter jasmine, camellias, heathers and quince are all favorites of mine and made to withstand the cold. How do they do it? Built in antifreeze, lots of sugar in the system lowers the freezing point making damage less likely. Perennials like hellebores and annuals like pansies may get whacked back temporarily but they are tough and can take it.

Early blooming crocus (USDA)
As for bulbs, some of my favorites are the ones that peak up out of the snow. There are the appropriately named snow drops as well as crocus, chinonodoxa and winter aconite. There are some early blooming daffodils, usually the smaller varieties but most of them along with tulips should still be just poking up some leaves. Once again, they are hardy and unless we have an epic Arctic outbreak it would be hard to have an impact on anything but a full bloomer.

If you are worried about vegetation damaged if we ever do see a true winter day, you can always heap on some mulch. That will help the plant to stay warm thanks to those toasty soil temperatures we have. Just be sure to uncover those plants when it warms back up.

For all of you with lawns: pray for a cool spell (unless you enjoy mowing)! Why is this?

Average temperature over last two weeks (Great Plains Regional Climate Center)
A good way to gauge when grass will green up is to look at the average temperature over the past two weeks. If it’s breaking the 40 F mark, then grass will be revving up the engines. As you can see (to the right), the Washington D.C. area is right on that 40 F line. It looks like temperatures should slip back a little over the next two weeks but will still be well above a 40 F average and may not save us from an early mowing season.

Another potential downside resulting from the lack of cold winter is the likelihood of more pests this spring and summer to deal with. I fear that Japanese beetles will be back with a vengeance. But that is the life of a gardener.

My last worry is that if the mild conditions are sustained, fruit trees could bloom early. One good hard freeze could then be bad news. If it is not too strong a cold event and you have a tree that is threatened, think about running a sprinkler under it. If you have ever seen icicles hanging of oranges in Florida after a freeze, that’s intentional. Farmers sprinkle the trees to take advantage of thermodynamics. When water freezes it gives off a load of heat. I know that sounds crazy but it has saved many a fruit tree from worse losses.

So come on people and let me know what is blooming out there and in a couple of weeks we can start talking about cold season veggies!

Capital Weather Gang meteorologist David Streit is also an active gardener. He earned a certificate in landscape design from the USDA Graduate School and volunteered many years at the National Arboretum.

Related: New USDA plant zones clearly show climate change

By  |  10:20 AM ET, 02/02/2012

Categories:  Environment, Local Climate, Latest, Gardening

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