Thoughts off the top of my head: August 2016
As most of you know, I travel quite a bit to see hostas across the country. This summer I attended conventions in Huntsville, AL, St. Louis, MO, Louisville, KY, and Champaign, IL. Yes, I was on the road four of six weeks in June and early July. Actually, where ever I wander, I see hostas and just check them out to see how happy they are.
No locality has a monopoly on all the best grown hostas, almost everywhere it is a mixed bag. Some hostas are spectacular and some look pretty neglected. Yes, neglected. Although many gardeners claim that they do very little for their hostas in the way of fertilization or irrigation, the hostas that are sited best in all locales tend to prosper the most. Highway median hostas can look just as rough in the Midwest as we would expect them to be in the South.
Every summer I come to some new understanding of some part of the world around us as it relates to hostas. Last year I think I rambled on about rainfall and the year before soils in Iowa. I never know where my mind is going; I guess I am just along for the ride. As I look back on it now, this year I put all those factors together and started to ruminate on where is the perfect spot to grow hostas. I know about microclimates and maybe next year we will look at that but for now let’s just look at the big picture.
In theory, if we look at the climate of Japan where hostas originate, we can get some clue as to what hostas like best to grow to their maximum potential. Unfortunately, Japan has a very variable climate and hostas have adapted to certain specialized habitats. Some are wet meadow plants, some forest plants; some cling to rocks high above rivers and others can be found in sun along the sea. It is as diverse a situation as the hostas that fill those places and spaces.
So what did I learn from this summer’s journeys? Huntsville, AL can support some great looking hostas. Whenever I give a talk on growing hostas I always include in it a slide that shows the local annual rainfall by month. Hostas need the most water when they are emerging and making new leaves and less in fall as they begin to go dormant. Huntsville receives 57 inches of rain a year, more than an inch a week and about 5 inches in both April and May when the hostas are making new leaves. Compare that to my garden that gets 42 inches a year and 2.5 inches in April and about 4 inches in May. April is our driest month.
We all know that hostas love water especially if they get it when they want it most. So despite the heat that will come later in the summer, it turns out that Huntsville is a great place to grow hostas because of the rains that fall as the storm fronts from the west are forced to lift over the tail end of the Appalachians.
This summer I also visited lots of hostas grown in lots of sun in locales with very hot summers. They looked great in June and a little fried in July but the clumps were dense, full with divisions, and very impressive. Hostas do like lots of light but will burn in hot sun; we all know this. The trick is balance. Cool sun may seem like an oxymoron but morning sun or dappled shade can provide just that. How much is enough and how much is too much?
This summer was my third trip to St. Louis to see some of these tour gardens. Some had lost trees, some had planted more trees and in some cases the trees grew like, well just like hostas, with all that water and fertilizer. The hostas in too much sun were already a little cooked but nice full plants. The hostas in too much shade and tree root competition looked worse. They were weak looking clumps that had diminished dramatically in size. Was it the lack of light or the competition from tree roots that was the culprit? Probably, a little of both but one usually comes with the other in a shade garden.
The moral of the story is that hostas would rather be in too much sun than too much shade. That maybe a little hard to swallow, but when in doubt push the limits, more sun is better. Of course this is safer in Northern gardens than in the South but is it really? Clouds make the best shade. A partly cloudy day is just dappled shade. Rainy days bring lots of shade along with water and nutrients. Locales that have many days a month with rain, 12-15 say, especially afternoon showers that help buffer against some of the heat of the day, may have enough “cloud shade” to support hostas in almost full sun. Just look out for those two sunny hot days in a row in July!!!
With clouds and rain comes humidity. Hostas were designed for humid climates. (Their close relatives the agaves were designed for low humidity.) The high dew points that we gardeners complain about constantly that result in “three shirt” days are paradise for them. Those big leaves can transpire lots of water. I have even seen huge clumps of hostas totally wilt to the ground in spring when the humidity drops and the breeze picks up even if the soil is saturated with last night’s rain. Others just burn; we have all seen those rusty brown spots especially on yellow hostas in the spring. Hostas need humidity.
Now bear with me, what I am now going to say is only a hunch. I really do not know but I am not the only one who thinks this way. Perennials in general seem to like cool nights in summer. Hostas are no exception. Morning dew must hydrate them to some degree and a little fog seems to perk up everything in preparation for a hot afternoon. Hostas grow best in climates where the summertime low temperatures fall into the 60’s. Our nighttime lows in the low to mid-seventies do not seem to refresh our hostas and in summer many just become a little heat dormant. I do not really know, but it makes sense to me.
Finally, the perfect locale to grow hostas has summer time temperatures in the upper 80’s and never above 92 degrees. Hostas actually grow very well at 92 degrees and high humidity; 96 degrees not so much. (Not enough heat can be a bad thing too, 80-90 degrees seems perfect for hostas.) Unlike cool nights, I am very familiar with hot afternoons. It always amazes me that when each year in August it cools off, highs in the upper 80’s and low 90’s, my heat dormant hostas start to grow again. Sometimes they jump! Hostas that never suffer high summer temperatures just keep going and going and growing.
So is there such a hosta utopia somewhere in this country that has lots of rain, cool sun, cool nights and no super-hot days, and humidity? A place with an inch of rain or more a week and maybe 3 feet of snow in the winter, where the temperature rarely reaches above the upper 80’s with foggy mornings and almost daily popup afternoon showers during the summer months? Maybe it would be in zone 6a with plenty of cold dormancy for hostas but not too brutal, with a long growing season but maybe at elevation, over 3000 feet.
I think I found that spot this year, Boone, NC. It is at 3333 feet elevation in the northwestern North Carolina mountains with bright sun but cool temperatures. Hostas there make tall lush clumps and are widely used as commercial landscape plants. Appalachian State University uses them extensively as well as the downtown district. These are hostas in too much sun but flourishing. ‘Blue Angel’ used as a border on the north side of a classroom building, ‘Minuteman’ in a parking lot. In May they were spectacular with the rhododendrons in full bloom.
So how did they look in late July? Yes, there was some burn on the most exposed hostas but really the only ones that were really fried were between the sidewalk and the street that had little soil and no irrigation. All and all they looked great, huge clumps that would make any Minnesotan proud. I am sure there are other places that combine all these characteristics but there is a certain magic to mountain hostas. I’d move there but there is not nearly enough flat ground for the nursery.
Hostas are often billed as low maintenance easy to grow perennials. Most gardeners assume this means dig a hole, stick the hosta in it, and walk away. Then magically a perfectly grown hosta will appear in the spring. This does happen in some spots in the space time continuum but more often than not hostas need a little help to succeed, maybe a lot.
Growing in containers is probably the easiest way to create a great environment for a hosta to enjoy. Many of the dangers of the real world, voles, tree roots, and slugs, can be eliminated but containers require more effort from the gardener. The pots need to be watered and fertilizer needs to be applied in a timely way. At some point that hosta will need a new, hopefully larger, container and require repotting.
I am not good at staying within the lines and tend to wander into the neighbor’s yard uninvited. On convention tours as others stand by the bus waiting for it to load, I head down the street to see how the local hostas are faring. Tour gardens house pampered plants, grown to perfection. But how are the hostas doing down the block at the house with the lawn that needed cutting last weekend?
I won’t mention the locale to protect the innocent (and guilty), but sometimes the neighbor’s hostas look spectacular and sometimes, well, they appear to be on death’s door. Some of this is how they are sited in the garden. The ones under the dripline of the roof along the foundation of the house usually appear pretty lush with all that extra water. The ones planted between the sidewalk and the curb, not so much. The soil may be more compacted near the street also, you never know.
So this begs the question, is abundant water all you really need to produce a presentable, if not show quality, hosta? It is definitely something to ponder but my nursery experience tells me that those sad, very flat hostas that I saw along a driveway needed a little something more than water.
We fertilize the hostas in the nursery each spring in theory just before they emerge. Each pot gets a pinch or two of slow release fertilizer depending on its size. Some years, like this spring, we do not have the woman power in April, our college girls do not arrive until May, and the hostas are already up, looking like blocks of mass plantings before we get out the fertilizer buckets. With all this foliage as a handicap, sometimes a pot here or there does not get fertilized. Within a month you can tell which plants were missed, they are weaker and more yellow. There is something to be said for nitrogen.
So it would seem that water alone will not produce a tall, fat hosta and that fertilization to some degree is necessary. Now before you start screaming at this little newsletter, I have heard many hosta growers tell me they never feed their hostas and they look just fine. Maybe so, but I wonder how much better they would look if they did. I think water and fertilizer go hand and hand.
But that is not all you need for a good looking hosta. You need light. Many hosta gardens, especially in the North, are too dark. Hostas do not prosper under a deck, and yes I have visual proof of this. Hot sun will also fry your hostas so light might be the trickiest thing to control in the home landscape. The house can offer bright indirect lighting and afternoon shade while the maple tree along the street may do more harm than good. And the more light you grow hostas in the more water and fertilizer they would like, but you know all this.
I always get back on the bus a little sad for those poor flat roadside hostas. They almost look like the neighbor’s teenage kid did a hit and run on them. Maybe hostas do need more care than we think. Maybe that’s why yours look so good.
Finally, I had cataract surgery this May and June. Surgery never comes at a good time but really May and June for a nurseryman. I knew it couldn’t wait when I went in our newly remodeled grocery store with LED lights and it felt like I was in the funhouse at the State Fair and driving in the rain at night became a foolhardy adventure.
As is the custom, I had one eye done and then about a month later had the other one done. This gave me the opportunity to put my scientific powers of observation to work and study the color of hostas. As you read this remember, blue and yellow make green.
We have all seen those catalog photos of blue hostas that were some unworldly “too blue” color. Websites frequently have similar problems with photos from both film and digital cameras. As I have gotten older, and my eye lenses more yellowed, I have become more and more vocal about how hard it is to capture the “real” blue of hostas in a photograph. I am most critical of my own photos as I play with the white balance on my camera to try to make the photo look like what I see, usually unsuccessfully.
So to make a long story short, I came home from my first surgery and as I walked past my hostas to the front door, (our garden is in the front yard so we are in it every day), I did a weird thing. I looked at ‘First Frost’ and ‘June’ first with my “new” eye only and then with my unrepaired eye only. Wow! The hostas through my new eye were really blue! They were almost digital catalogue blue. Using my other eye only they were much greener. Blue and yellow make green.
For the next month, I enjoyed my hostas one eye at a time until I had the second eye repaired. Then the hostas were equally blue one eye open, the other eye open, or both eyes open. All this leads me to perception. I am sure that I now see blue hostas more realistically without my old yellowed lenses but there is no way for me to tell. They just look, well normal, not super blue anymore. It is kind of disappointing that our brains take what we see and show us what we think we see. Without comparing and contrasting, analyzing the world around me, my life is simpler but to me it is a little more boring, too. I miss my cataracts, at least the one in my left eye.