After a mid-April snow storm, things in the prairie may be on hold, but the greenhouse is abuzz with activity.
One of the nice things about growing native plants in the greenhouse is that the temperatures can get below freezing in there, as they are at night even in April this year, but that doesn't bother the native grasses and wildflower plugs. For most vegetables--but not all--below freezing temps means death.
This means that I don't have to turn on the heat and worry about keeping things above freezing, which this winter and spring would be quite expensive. The greenhouse warms up nicely during the day but gets below freezing at night.
The temperatures may get below freezing in the greenhouse at night, but they stay above freezing in the little galvanized structure you see in front of the greenhouse. That structure is where the water pump is. Pumps must not be allowed to freeze; if they do, the ice in the pump will expand and break the pump (something that's happened to more than a few of my pumps). I have a small heater in that house, which allows me to keep it from freezing, so that I can water the plugs during the day when the temps in the greenhouse can be quite high, but then close it off in the pump house so it won't freeze when the temps drop at night.
It is worth noting that many plants (including forage crops and vegetables) fall into two categories: cool season plants or warm season plants. It is something many of us are unaware of, but it is a big deal in the plant world. Think, for example, how green the turf grasses of the average residential lawn are in October, and how beautifully the grass contrasts with the brown corn stalks we see on farm land. This is because Kentucky bluegrass is a cool season plant, and therefore thrives in the cool weather of October, but corn is a warm season plant that thrives in the heat of summer and dies after a frost.
When it comes to weeds, it is important to know whether they are warm season or cool season plants. For example, Reed Canary grass is a big challenge to prairie restoration work. It's an aggressive non-naive grass that is hard to get rid of. But knowing that it is a cool season plant allows us to, for example, spray it in the fall (even in October) to get a good kill. Herbicides are most effective when plants are active, and are much less effective when plants are inactive. So spraying Reed Canary grass in September and October allows the herbicide to be more effective.