There was a lot to take in as far as the gardening world over the past few months.
First, we had the winter that wasn't, and then we were surprised by the news that the Department of Agriculture has put us one full zone warmer, from 5a to 6a, with just the click of an enter button on the computer. OK, it was a bit more complicated than that, but it lit up the faces of gardeners who envy warmer climate plants and made skeptics of others who know what it's like to live and garden in northeast Ohio. I'm sort of in-between.
My wish for this season is to see lots of blooms on my Nikko Blue Hydrangea, a plant that many people receive as gifts on spring holidays such as Easter and Mother's Day, without realizing this variety of H. macrophylla isn't likely to bloom again, especially after a particularly cold winter.
Depending on where you buy this plant, the tag might will say it is hardy to zone 6, or it could say it is hardy to zone 5. For those not familiar with the USDA's plant hardiness map, the department basically divides the United States and Canada into sections that it calls ''zones.'' These zones are determined by the coldest temperatures the area can drop to in winter. Growers tag their plants based on how their survival under those conditions. The zones range from 1 to 15. The higher the number, the warmer the climate, so areas such as southern Florida and south can grow tropical plants, while northern Canada is the lowest with extremely cold winter temperatures.
Prior to the announcement last fall that our zone had changed, we were 5a. (The letters, a and b indicate sub zones with a as colder and b as slightly warmer). Most gardeners, however, don't pay much attention to the sub-zones. After taking calculations over the past 30 years of our average winter temperatures and our topography, the USDA determined our area was getting warmer in winter and instead of average temperatures of 20-below zero, we were now in the 10-below zero range. This doesn't mean we won't get colder temperatures than 10-below in winter; it just means that's our average.
Now back to the Nikko Blue. H. macrophylla, a big-leaf variety and probably the most gifted of all the hydrangea varieties, has always been hardy to zone 5. That is, the plant is hardy. The flower buds, which grow from the previous year's growth, are not. So while we have lush, lovely plants with big leaves and lots of branches every summer, there may or may-not be any of those huge, softball-size blossoms that can change from pink to blue depending on your garden soil. Cold winter temperatures will kill last season's stalks from where the flowers grow. New growth comes from the plant's crown just under the soil surface, but flowers won't form on those stalks until next year. Get it?
I've had a Nikko Blue in my garden for at least 10 years. Someone gave it to me, and I planted it, knowing my chances on getting flowers. I tried mulching as some of my gardener friends recommended, and I've tried massive doses of triple-super phosphate and other blossom encouraging fertilizers. Some years I might have gotten a blossom or two and other years nothing.
Each season I tell the husband, ''Don't prune those dead stalks off the hydrangea just yet. Let's wait and see what happens.''
Usually what happens is we end up pruning off the dead stalks from last season.
Maybe this is the year? Maybe our mild winter with above normal and record breaking temperatures really does mean we are in zone 6a after all. Maybe it does happen overnight (probably not), but gardeners are optimistic.
Sure I have other hydrangeas that always produce flowers. The variety of macrophylla, Endless Summer, that blooms on current year's wood will give me a few blossoms, but I've always been disappointed in this plant's ability to produce very many flowers. Paniculata hydrangeas commonly called PeeGee's, and H.macrophylla normalis, also known as lace-caps, both do well here and will bloom every year, as does the heirloom variety Hydrangea arborescens, 'Annabelle.'
But this year, of all the plants in my gardens, it is the Nikko Blue I will have my eye on more than anything else.