April Warmth

April 2014

PICKAWAY TO GARDEN

April Warmth

By Paul Hang

I can hear it now, (not really, I won’t be around) in 30 or 40 years today’s kids will be talking about the winter of 2013-14. “In my day we had real winter.” This has been quite a winter but not as bad as in my day (the blizzard of 1950). All this cold is retarding the arrival of the signs of spring. Some trees are beginning to bloom but their flowers are pretty insignificant. We can see a blush of color, usually a mist of green, bronze or red. We are way behind last year.

"April showers bring May flowers." That old saw reminds us that water is essential for plant growth. May flowers (and April flowers) are just as dependent on light and especially the warmth of the air and the soil. Those flowers will be here whether we have showers or not. The warmth of the soil is crucial for the flowering of plants. Some plants need more warmth than others. Forsythia blooms earlier than lilac.

To find out how much warmth it takes to bring on the bloom of certain plants you can go to www.oardc.ohio-state.edu/gdd. This site will ask for your Ohio zip code. It will then tell you what the present value is of growing degree days and the corresponding plant that is in bloom. For instance, as I write this (March 24^th) the growing degree day value for zip code 43113 is 42 and Silver Maple is in full bloom. The growing degree day (gdd) for border forsythia is 86. The gdd for common lilac is 315.

“Growing Degree Day (gdd) is the measure of the growth and development of plants and insects and it is directly related to the daily maximum and minimum temperature.” The value of gdd is cumulative. As the days get warmer the gdd value increases. A cold spell will slow down or even stop the increase in the gdd value. A hot spell will speed up the accumulation of the gdd value. Another example, Rose of Sharon is in full bloom around here when the gdd reaches 1347 which usually occurs at its earliest in June.

This information is the result of research which was carried on across Ohio in the past, a lot of it by Master Gardener Volunteers who recorded the dates when certain plants bloomed in their area. Pickaway County has a Phenology Garden of indicator plants in Five Points which is maintained by Master Gardener Volunteers. Phenology is the name for the study of the correlation of events in nature. (Phrenology is the discredited study of the bumps on our heads.)Thomas Jefferson maintained these kinds of records for decades. It is also found in folklore or “Old wives tales” such as “Plant corn when the oak leaves are the size of a squirrel’s ear.”

The system was developed to anticipate when insects reach a stage where pesticides will be most effective in their control. This saves money and the environment. Another example, Eastern Redbud blooms when gdd reaches 191 and Gypsy moth eggs hatch at gdd 192. Spraying the new hatchlings is more effective than spraying the eggs or the adult moths. However the optimal time to spray for Gypsy Moth is gdd 365 when Black Cherry blooms. The system can be used for correlating other phenomena with the bloom of certain indicator plants. The weather will warm. In fact growing degree days are already accumulating, really. Stay strong. Remember we’re all in this together.

.April 16^th is Ralph C. Starkey Community Action Day. One of the activities will be held at Mary Virginia Crites Hanna Park. The volunteers will work to remove as many invasive plant species growing in the woods as we can. Come join students from Ohio Christian University, local high schools and others. Bring loppers if you have them.

Things to do in the garden:

Helpline. Pickaway County Master Gardener Volunteers will be available to answer your questions about gardening. Call the OSU Extension office at 474-7534. Your question will be taken and then a Master Gardener Volunteer will get back to you with an answer. You can also pose a question at the OSU Extension website, pickaway.osu.edu, click on the "Ask an Expert" button.

If you are a serious gardener or just want to learn more, make a weekly habit of checking the Buckeye Yard and Garden Line at BYGL@osu.edu. There local state experts discuss gardening issues which are in the form of a newsletter.

Time spent on your lawn now will benefit it the rest of the year. Fertilize lightly. Now is the time to re-seed once night time temps consistently reach 50 degrees. This is also the time to aerate lawns. April is the time to apply a pre-emergent (but not if you plan to seed) to prevent crabgrass and other annual weeds in the lawn. A rule of thumb is to apply when the forsythia is in full bloom. Leave those first clippings on the lawn. Their nitrogen content is high. Mowing height at least three inches will retard the growth of crab grass and other weeds.

Unless you are prepared to cover plants in case of frost, don’t put out those tender plants such as tomatoes and peppers until the end of the month. The average last frost date is now April 23rd. There is a 50/50 chance of frost then and the chance decreases about 10% per week after that. Spring flowering bulbs should be fertilized after they bloom. Remember to leave the leaves of bulbs until they yellow. Brown is better. Also prune spring blooming shrubs after they bloom. If April brings its overhyped showers don’t dig in our clay soils until they dry out a bit. If they seem wet enough to make a clay pot, wait.

Cut back your ornamental grasses to a couple inches. Cut back your butterfly bushes (buddleia) to a foot or two and apply a balanced fertilizer. Pull those bag worms, or better, cut them off. Do it now before the worms hatch out. Dispose of the bags in the trash or bury them. One bag left equals a hundred plus new bags that won’t show themselves until this fall.

It's not too late to start tender plant seeds indoors to be placed in the garden later, after hardening them off, and the danger of frost is past. Tomato seedlings should be moved from the cells after 4 weeks into a larger pot or into the garden (if weather permits). As usual make sure you water in the transplants.