In 90 Seconds: How to take care of outdoor plants during a winter freeze
We gardeners have benchmark times – dates that trigger thoughts of things that have to be done at those times. And such it is with late winter. It’s last call for the tasks I’m about to outline. Better check through them. There may be a few that have been hanging around on your mind for a while.
Transplant established trees, shrubs
If you have woody plants that need a new home, or if you’ve spotted a plant out in nature that you’d like to bring into your gardens (with permission, of course), you must do that moving during the dormant season. That means you have two or three more weeks to accomplish the task.
Dig woody plants with their soil kept firmly intact around their root systems. Use a sharpshooter spade for the cleanest cuts, and use loppers or a pruning saw if you encounter larger roots. Wrap the balls of soil in sheets of burlap to hold them together. Secure them with nails. Plant the transplants at the same depth at which they were growing originally, and firm the soil around them. Stake and guy them as needed to hold them upright. Prune to thin out the top growth in compensation for roots lost in the digging. Water deeply, and apply a liquid root-stimulator fertilizer monthly the first year.
Plant early vegetables soon
Asparagus roots should be planted into the back of your vegetable garden where they can remain undisturbed for many years. Set the roots in trenches 10-12 inches deep and 15 inches apart. Space the rows 6 feet apart. Cover the roots with 4-5 inches of loose topsoil, gradually filling the trenches as the spears start growing.
Plant onion slips now. Choose types that are well adapted to springs in North Texas. 1015-Y (Texas Supersweet) is still the most popular. Space the plants 3 inches apart. Plant them shallowly. Expect 10-15 percent of the plants to fall over after you water them. That’s evidence that they’re planted at the right depths. Set them upright and firm the soil around them again.
Other vegetables to plant soon include snap-type English peas now and, by mid-February, Irish potatoes and potted transplants of cabbage, broccoli, Brussels sprouts and cauliflower.
Finish dormant-season pruning immediately
This is a fairly lengthy list. It includes evergreen shrubs. Try to maintain their natural growth forms rather than shearing them into formal shapes. Prune summer-flowering shrubs and vines now, but never “top” your crape myrtles.
Grape vines to remove as much as 80 to 85 percent of their cane growth as you train them along their trellises.
Prune peaches and plums to maintain horizontal branching and a bowl-shaped growth habit. Trim apples to remove strongly vertical shoots (“watersprouts”).
Watch for scale insects on shade and fruit trees, shrubs
These immobile, sucking pests can rob the life from fruit trees, euonymus, hollies, camellias and other plants. Apply dormant oil (“horticultural oil”) to their trunks, branches, and leaves according to label directions. If you have had a problem specifically with crape myrtle bark scale in recent years, this dormant oil treatment will not offer much control for it. Treat for it with a systemic insecticidal drench in mid-May.
Treat broadleafed weeds before they bloom and go to seed
We’ve had enough balmy spells over this winter that the non-grassy weeds have become robust and unsightly. During one of the late January/early February warm spells (60 degrees and above) when it isn’t going to rain for a couple of days, apply a broadleafed weedkiller containing 2,4-D to eliminate henbit, clover, chickweed, dandelions, wild carrot, thistles, plantain and all the miscellaneous “barnyard” weeds that crop up in our lawns this time of year.
In fact, you might try just mowing them out first. Many of these broadleafed weeds are so succulent that they lack the ability to regrow once they’re cut. It may even be easier just to hoe many of them out.
Unfortunately, I have no comparable control to offer for cool-season grassy weeds such as annual bluegrass, rescuegrass and ryegrass. Your only way of dealing with those is to apply pre-emergent granules in the last week of August or first week of September. Once they’re up and growing there is no way to eliminate them.
Have your soil tested now to avoid the rush later
It’s a good plan to check nutrient levels every three or four years to monitor shifts in nitrogen, phosphorus and potassium, also accumulations of mineral salts. While you’re at it, have the pH (acidity/alkalinity) tested, too. Be prepared to see extremely high levels of phosphorus if your native soil is a clay. Phosphorus dissolves very slowly and if you have added it in past growing seasons, much of what you added is probably still there. As a result, it’s very common to see recommendations of nitrogen-only fertilizers, not only for lawns and landscapes, but also for flowers, fruit and vegetable gardens. Trust those results and fertilize accordingly.
Some local nurseries offer soil tests in the spring. You can also use the outstanding Texas A&M Soil Testing Laboratory. Sampling and mailing instructions are found at their website http://soiltesting.tamu.edu.