Upcoming cold not a bad thing for gardens

Coming up at 1 p.m.: Live video discussion of Sunday snow chance

Washington, DC - March 20: Bright yellow daffodils blossom at the George Mason memorial. (Photo by Bill O'Leary/The Washington Post) (Bill O'Leary)

We have entered a stretch of unseasonably cool weather and this will be worth keeping an eye on. This can be a blessing in disguise for the garden as it keeps the pace of blooming and emergence a little slower and less likely to be affected by freezes. If you have newly emerged vegetables or flower seedlings be particularly aware of any nights where the temperature is forecast to stay below freezing for 4 or more hours. That is the period of time needed to chill things to the point of causing damage.

Our own National Weather Service site has a nice product called the hourly weather graph which allows you to take a quick glance and see what the next two or three days hold in store. Of course that is no substitute for our own Capital Weather Gang forecasts mind you, but it is a help in deciding whether to cover things with some plastic for the night. As I noted in an earlier blog, painter’s plastic from the hardware store over the plants helps to hold in heat and avert freeze damage. Just be sure to get that plastic off the next morning by sunrise or you will quickly roast those plants.

Now how about our beloved cherry blossoms? The Tidal Basin is a great reservoir of warmth to protect the blooms. So as long as we don’t have a sub-28 degree night with winds of 10 mph or better, damage would not be expected. The buds are swelling quickly now and some trees are already starting to bloom. What is really great is that the next two weeks of weather will just about encompass the bloom period and right now it looks cooler than normal with only light winds and gentle showers of rain or wet snow. That is a perfect scenario for making those blooms last.

As for other blooms, the stars are really the bulbs now. There are several gardens on the National Mall that provide great displays of these beauties, as does the National Arboretum and a host of local gardens.

This is a great time to check them out, decide what you like and get ready to plant some of your own next fall!

As mentioned at the top of this article, this time of year can be one of rapidly fluctuating temperatures and heavy downpours. It is a good time to get some mulch down and help buffer plant roots from those temperature extremes and it can help to cut down on some of the erosion that occurs in a typical Washington spring thunderstorm. It doesn’t look like there will be much of that in the next 10 days but they will come. Next time they do, take a look at your garden and note if you have drainage problems or places of rapid runoff. It is a great idea to plant some ground cover in areas that are prone to erosion. There are plenty of good plants for this area including ivies, creeping juniper, cotoneaster and many more. This will help to keep moisture in place when those inevitable Washington dry spells set in.

Now is a great time to be in the garden before the heat of summer returns!

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.