Gardeners can delay winter pruning until early spring

            With last spring’s late freeze and last fall’s drought, people should hold off on winter pruning until plants and trees start to show signs of development because some may come out of dormancy with additional damage, said Richard Durham, University of Kentucky associate extension professor of consumer horticulture.

            Typically, winter pruning is done between mid February and mid March after most of the severe winter weather has subsided, and it is just before spring – one of the busiest times for plant growth. However, because of last year’s unusual weather, people can wait to prune as late as the end of March to early April, Durham said.

“Regrowth is usually evident by early April as buds begin to swell and grow,” Durham said.  “If parts of the tree or shrub are not showing renewed growth while other parts are, these sections are likely dead and will need to be pruned away.”  

When most people think of pruning they think of their shade or fruit trees. However, for shade trees, pruning should mostly focus on correcting damage and promoting healthy growth.  Dead branches, branches rubbing together or crowding the trunk are all reasons for pruning, he said. Thinning out diseased or unproductive branches to the tree’s trunk or major limb, improves the tree’s health, making it more open to receive additional sunlight and air movement. Heading back cuts, which remove only the terminal portion of a shoot, encourage the development of side branches and stiffen the remaining branch. This can be particularly useful for apple and pear trees, whose branches should be trimmed to support a heavy crop load.

Shrubs are pruned to maintain a certain shape or size. Flowering shrubs, like lilac and forsythia, should undergo rejuvenation pruning each year so the shrubs will flower more. This type of pruning removes between one-fourth and one-third of old growth each year and encourages new growth. For example, forsythia only blooms on recent growth while lilac can bloom on older growth, but more recent growth from the past 2-3 years is generally most productive.

It is important to not go overboard with pruning. While some trees are excessively pruned at the top because they encroach on utility lines, for the most part intensive pruning is not needed and tree top pruning should be avoided. Painting or sealing cuts is not necessary and may actually delay the regrowth that helps the tree recover from pruning.

Writer: Katie Pratt, 859-257-8774

UK College of Agriculture, through its land-grant mission, reaches across the commonwealth with teaching, research and extension to enhance the lives of Kentuckians.

 

TIPS FOR SUCCESSFULLY STARTING VEGETABLE, FLOWER SEED INDOORS

         Starting seed indoors enables gardeners to select the exact varieties they want for vegetable or flower beds, whether an heirloom tomato or new zinnia variety.  There are other benefits from having a variety of home-grown vegetables and flowers.  One of the most satisfying is to say, “I grew these myself, from seed.”

        Vegetable seed that are easy to start indoors include tomatoes, peppers, squash, cabbage, eggplant and cucumber.  Marigold and zinnia flower seed also are simple to start inside.

        Garden centers and mail-order catalogues offer many varieties from the newest and improved ones to favorite standbys.  Too avoid buying too many seed, calculate how many plants of each variety are needed for the garden.

        For greater success starting seed indoors, don’t plant them too early and give them adequate, but not excessive, water and sufficient light.

        Seed planted too early result in overgrown plants that are yellow, crooked and spindly before it is even time to transplant them outdoors. Thus, it is critical to properly time the planting of new seed so young seedlings will be large enough to transplant in the garden when the danger of a  late frost is over.

        To determine when to start the seed, check the outdoor sowing time on the seed packet or last late frost date for your location. In western Kentucky, the last date for a late frost generally is the last week in April through the first week in May; central Kentucky, mid-May, and eastern Kentucky, last week in May.  Plant seed three to four weeks prior to the recommended seed packet date, or time for the last late frost.   An exception is squash and cucumbers, which require only seven to 10 days for seedlings to grow large enough to transplant in the garden.

        When it’s time to plant seed, gently press potting soil into each small container; add two seeds per container at the depth recommended on the package, and put the containers in leak-proof trays.  Unless you are using a peat product, be sure containers have at least one drainage hole.

        Then, slowly water each small container to saturate the potting mix, using slightly warm tap water.  Never allow containers to sit in standing water. Throw away excess water that seeps into the trays.  A kitchen baster is a good tool to remove surplus water.

        Put the leak-proof trays in a warm location such as the top of a refrigerator or freezer to help seed germinate, usually in seven to 10 days.  A sprout emerging from the potting mix indicates germination.

        Plants need a bright area to grow indoors, but unfiltered sunlight will dry out the containers too quickly.

        After seed germinate, move the trays to a south window or sunroom with filtered light. An alternative is to put incandescent or fluorescent bulbs six to eight inches from the containers to provide light necessary for germination. Leave the lights on all the time, and occasionally rotate plants that begin to grow towards the light source.  Fluorescent lights are preferable because they do not get as hot as incandescent lights.

        A hot bed or cold frame may be a good investment for gardeners planning to produce lots of seedlings to transplant each year.

        It is critical for newly-germinated seedlings to have water available for the next two to three weeks, so frequently check the moisture content with your finger to keep from damaging tender roots.  Carefully and consistently water when the soil feels dry a little below the surface for the first two weeks.  You can slowly apply a water-soluble fertilizer the third week.  Be sure to follow instructions for the amount of fertilizer to use.

        To avoid common problems starting seed indoors, use a high-quality starter mix, don’t plant seed too early; select a warm area to germinate seed; provide a high-light environment for seedlings to grow; and keep developing seedlings moderately moist.

 Sources:  Richard Durham and Tom Priddy, UK Cooperative Extension