Farmers Weekly Review

Ahhh, Mother Nature … you and your fickle thermostat. First, you lure us into this non-winter winter, then you dial down the thermostat radically, to the 20s, just to run a shiver through every gardener, and all those trees, shrubs, perennials, and bulbs that were fooled by your fake spring in February.

So, what is a gardener to do?

First, don’t panic. The likelihood of the dizzying warm-hot-freeze cycles of early spring killing your perennial plants outright is very unlikely. But who grows a tulip or lilac for the leaves? Two of the top questions I am asked this time of year are: When is it safe to uncover plants from their protected winter mulch, and how soon should I clean up the garden?

And just like any good politician (or scientist) the answer is … it depends. We have had killer frosts all the way deep into May, May 22 to be exact. A couple years in the teens of the 2000s, Illinois and Indiana lost much of its tree fruit crops to a 14-degree freeze late in May after having had a non-winter winter. Sound familiar? Many orchard farmers were buying produce out of Michigan to shore up their dearth of their own apple harvest.

Wait, did I say Michigan? Isn’t it colder up there than in Illinois and Indiana? The answer is, definitely yes. And that is why their fruit was saved. The problem for us here in the Midwest rollercoaster temperatures, is that plants respond to environmental cues. Just like humans, regardless of predictions, the weather can change dramatically anytime. You know this syndrome. When you dress for the morning weather, cold, windy and cloudy; then by noon, you wish you had shorts and a tank top on.
We had warmer weather so our trees, shrubs, bulbs, and perennials, started to disrobe by taking off their protective bud coverings. Then, the unprotected bud starts to swell, preparing for a glorious, floriferous display. Then bam! 15-degrees. Only one night, but that is all you need.

Bud blast is a term for buds that were damaged for some reason and do not come to fruition. This can happen for any number of reasons, but the common one for our area is the buds that had formed on the plant start to swell and are either damaged or killed outright by a late frost.

Note I said killed the bud, not the plant. The tree, shrub, bulb or perennial will still grow throughout the season, but a few, some or all of the flowers for this year may be lost.

Can you prevent this from happening? To some degree, yes. And not by bribing Mother Nature to keep cold, cold, and hot, hot. The choices are relatively easy.

First, you can keep your winter mulch on or nearby until Memorial Day (kidding, not kidding). Remember, winter mulch isn’t the wood chips you have as a layer around plants throughout the year to suppress weeds and keep soil moisture and temperature even.

Winter mulch is something placed on plants after the weather has turned fully cold (late November — a good post-Thanksgiving dinner activity) where you place light branches (evergreens are ideal) over the upper parts of spring blooming shrubs to keep them insulated cold, so the warm snaps don’t start the buds unfurling too early.

You can also use burlap to cover particularly sensitive shrubs. Hydrangeas fall prey to the late-frost bud blast often. Once again, the plant is fine, but gardeners report no blossoms. If I get them to investigate further — to look along the branch for the conical flower buds, now brown and dead — they find the answer.

As far as bulbs are concerned, once again, daffodils reign supreme. First off, daffodils are totally poisonous to wildlife, but tulips are like M&Ms to kids. Frost related; daffodils are smart. They send up their leaves first, and then bloom later. But tulips, not so bright, the flower bud emerges right with the leaves, more likely to be hit with a late frost.

Often bulbs that emerge too early are the ones that weren’t planted to correct depth, although that is not the case this year. Remember, bulbs are to be planted three times their height. So, a nice 2-inch tulip bulb should be 6 inches deep. When they are planted too shallow, the soil at that depth warms too quickly, and the bulbs think it is bikini season, when in reality, a parka is still in order.

Keeping some branches, leaves, or a thin cotton sheet to throw over these bulbs if a cold snap is predicted is a sound practice. But never, ever, cover in plastic. Will it keep the frost away? Yes, but if it is not removed prior to the sun hitting it, you have a recipe for disaster, creating an impermeable greenhouse effect.

This is true for all plants. I have heard this sad tale more than I care to remember, especially when it comes to the vegetable garden. Gardeners cover their tomatoes and peppers — that they should have waited till Memorial Day to plant — and if they use plastic and don’t remove it before the strong sun comes over that area, they are at the garden center buying another set of seedlings.

But what do you do when you can’t cover a plant, say an apple tree covered in blossoms? Misting the whole tree with water, although difficult to achieve, is a frost protector. That is what they do in Florida for the citrus and strawberry crops. This isn’t watering the soil; this is misting the fruit and flowers.

Amazingly, the ice forms around these precious plant parts, and the water freezes, not the blossoms or developing fruit.
Midwest weather. It always keeps us guessing.