Thoughts for the Gossip Jr. August 2014
I like to think of myself as an amateur meteorologist. In fact I do need to forecast the weather as part of my job growing hostas. On those frosty April mornings I need to know if it is going to be 31 or 33 degrees at sunrise; a degree or two here or there can mean putting all the plastic back on the hoop houses or leaving it rolled up in the basement. After all these years, I have gotten to know the microclimates of my nursery pretty well.
I also dabble in climatology. No, not long range changes in climate but short term trends. Will it be a dry year or a wet year, generalizations not specifics? Although, I have ridden out maybe two dozen hurricanes and could track them even before we had all the Doppler radar we depend on now, (we mapped barometric pressures), I would never try to predict how many there would be in any given season.
Last summer was unusually cool and very wet. Mushrooms and other fungi appeared in mass by July. According to my theory, rainfall cycles and the accompanying temperature data run in about 18-24 month cycles. Lots of rain brings lots of clouds and usually lower temperatures, with cold fronts passing through the state or getting stuck here for days. If the Bermuda High drifts westward over us, then it will be hot, cloudless and thus very dry. We were wet and cool last year and I figured we would be hotter and dryer this year.
Everything seemed on schedule as the temperatures rose to the upper 90’s in mid-June. (Fortunately for me, we were in much cooler Iowa at the Hosta Convention during that week.) We even had a little hurricane skirt the coast bringing lots of rain at the beach but just a single small shower inland. But then the cold fronts started to push down again from Canada, much like they did last winter and with them the rain in copious amounts.
We have not had the weeks of rain and clouds like last year, it has been drier and warmer, although rarely hot. We had almost 3 inches of rain last weekend and today, Saturday, it has rained all day. All day rain is uncommon in the summer in North Carolina, but here we go again. Is the climate changing? Maybe, but probably it is just on a much more complex cycle than I or other climatologists ever imagined.
All this brings me to hostas. We all know that in a spring with lots of rainy days, our hostas will grow taller and the leaves will be larger than normal. Yes, the abundant water has a lot to do with this but also the reduced amount of light the plants receive. They are getting extra water but extra shade, too. In dry years this is reversed and our hostas are shorter and their leaves are smaller and maybe even a little less rounded.
But there is more. Temperature variations when our hostas are rapidly emerging in spring also have a great effect on their eventual shape and height. Periods of very warm days followed by cool days with the lows approaching freezing at night are common in the South in early spring. My hostas will expand rapidly in the warmth and then stand still on the cooler days. This starting and stopping will reduce their ultimate size. Long periods of cold when my hostas are about half way to maturity may stop their climb upward all together. Maybe that is one reason, (although probably not the most important one), that hostas tend to be shorter in the South than in the North.
Just when you think you have them all figured out, you find hostas are also more complex than you ever imagined. Take hosta hybridizing. Some things are still easy, H. sieboldiana types, including ‘Dorothy Benedict’ and its seedlings, always seem to set lots of seed. But do they if they bloom in the heat of a North Carolina July? The answer is, “Yes, pretty much”. Easy peasy!
Other hosta species and their hybrids are more complex. Hosta seedlings with several species in their background may be a little out of sync. The pistil is receptive early in the morning but the pollen does not ripen until just before noon. Even the time the flowers open may vary widely in these complex crosses, especially with H. plantaginea as a parent.
Summer weather will drive you crazy with all this pollen, pistil timing. On a “normal” day the pollen will be ready to use by 9:00 in the morning. On cloudy days the pollen usually is released in late morning, unless it is very dry. High humidity will retard the pollen also but only some days. Sunny days are best unless they are following very cool nights, then the pollen might not be ready until almost noon. Some seedlings are usually ready to go no matter what but fragrant flowered hostas and many of my red petioled hybrids with multiple late flowering parents can be very slow to open for business. Got all that?
As fall approaches in late August, everything slows down. Some flowers even stay open for more than one day. (That can get confusing!!!) It is often 11:00 before I can use some of the pollen on almost every day. Fortunately, I have very good luck setting seed in September and have a long enough growing season so that the seeds will ripen before frost.
So every day I play weatherman and try to guess when the pollen will be ready. I am getting better at it but I can still predict the late spring frosts with much more accuracy. What I really want is a climate controlled hybridizing house. It would be hybridizing heaven where every day is the same and the pollen is always ready, and every pod sets. It would be so easy, only it would probably take me years to figure out all the right settings for light, temperature, and humidity. Then there would probably some of my seedlings that would still be stubborn and not play along anyway. It is still a wonderful dream.
By the way, it is still raining. Next year the drought returns. Write it down!
While we are talking the difficulties of hybridizing, which hostas are the most difficult to produce? Which should be the most expensive to buy? We all know the easiest hostas to hybridize, green ones. Well, yes, but blue ones and yellow ones can be easily produced from just a single cross. Variegated hostas, with the huge number of streaked parents available now have also become pretty easy to create. Getting them to look different and not melt away is a little harder.
Medium-sized hostas are easy too. It is the default size for almost cross. Really large hostas are difficult but mostly because you have to grow them for years and years, through wet springs and drought, before you know if they are really gigantic and not just large. Minis on the other hand are tough!!! Cross two minis and most if not all of the seedlings will be bigger than their parents.
So what are the rarest hostas? Which are the most difficult to produce and what traits are the hardest to pass along to the next generation? If minis in general are difficult, then blue minis are almost impossible. Can you even name five really blue miniature hostas? I do not know that any pop into my mind. ‘Baby Bunting’ is the classic blue mini but it is not very blue. ‘Blue Mouse Ears’ is not very blue either, is certainly on the large side of miniature, and is disqualified anyway because it is a sport. My ‘Baby Blue Eyes’ is pretty blue but a little large.
The problem is that all blue minis have a large H. sieboldiana somewhere back in their family tree. You can only shrink that plant so much. Even if you inbreed generation after generation of little blue hostas like Herb Benedict did to produce ‘Blue Chip’ and ‘Blue Ice’ in an attempt to reduce plant size and increase blue color, success is difficult. Yes, the plants are small but they are small because they grow very slowly, not because they have small genes. This method of hybridizing does produce a small very blue hosta but not one that is much fun for hosta collectors to grow.
The answer is to combine small genes from different green miniature hosta species until you have the perfect vigorous little mini and then somehow in one cross turn them blue, using the pollen from the smallest very blue hosta you can find. Grow lots of seeds because you will get lots of small, (and probably even some medium-sized seedlings), but maybe, just maybe you will get one that stays small and is vigorous.
The next degree of difficulty is to try to give your perfect blue mini fragrant flowers. Using the pollen of H. plantaginea you can transfer fragrance to your seedlings in a single cross. You will also transfer a lot of other characteristics from H. plantaginea, leaf color, large flowers, shiny wax, and large size. All this will make you seedlings larger than minis and less blue. They will however be pretty vigorous. A second cross or two will be necessary, maybe back to your perfect blue mini. Unfortunately, most, if not all of the H. plantaginea seedlings will be sterile and not useful in continuing your breeding line, creating a dead end. Hopefully through patience and good luck you will find that one special fertile seedling and your line can continue.
Let’s say you pull it off. You have a blue mini with somewhat fragrant flowers, even if they are a little too large in proportion to the clump size. Let’s say by some miracle it is fertile or at least the pollen is viable. (All these crosses can be made either way but I like using the mini for the pod parent if possible so that the inherited organelles, chloroplasts, mitochondria, etc., are from the smaller plant.) Now let’s make the petioles and scapes red!
In my pallet of plants, I have a few small blue hostas with some red on the petioles and colored scapes. These are from multiple crosses since H sieboldiana has no pigment on its scapes. The “Tardianas” are a good place to start; they have purple pigments from ‘Tardiflora’. I have used ‘Blue Blush’ because it is small and slow. Its seedlings make small to medium-sized plants. It will probably be a two generation project but is doable. Red, or in this case purple, is easier to add than fragrance.
You can start the process at this end if you would rather. Make a small blue with red petioles, make it miniature, and then add the fragrance. It might take as little as six crosses, but probably more like eight and a whole lot of luck. At three years a generation, it is about 20 years of work. The consolation prize is that you will produce lots of cool little plants that you can name along the way, maybe a couple of great ones.
Next project: produce a very large, upright yellow hosta, (that doesn’t burn), with red petioles and scapes. The fragrant flowers can be optional this time.