Sunday, April 4, 2010

100 Degrees in the Shade

It is unseasonably warm in Virginia -about 20 degrees above the norm for this time of year. This means it is 120 degrees in the greenhouse, and even the tropical water plants are wilting.

This calls for some sort of shading on the southern side. The first summer we built the greenhouse, I planted mammoth sunflowers on either side, thinking it would be a low cost alternative for shade, as well as a food source for the birds. The sunflowers were beautiful, but weren't thick enough to block any degree of sunlight.

The two following years I simply moved plants out when it became too hot inside, and sacrificed the use of the greenhouse for the summer months.

This year, I really want to see how long I can stretch out the growth season for both lettuce and spinach (both cool weather crops).

So this year I purchased a 60% shade cloth. This means the weave blocks 60% of the sunight and UV rays. Not only will it keep the temperatures down, but it will protect the outside wood a little more from the sunlight. The one I chose is black, but they also come in white, green, and tan, in a cariet of sizes. (Source: CatalogClearance) Order a larger size than you think you'll need, particularily if your greenhouse has a gable roof. Voice of experience here.

The shade cloth comes with both finished edges and grommets. Ours is anchored at the bottom with a 12' length of 1" PVC pipe. We drilled holes to match the grommet spacing, then ran zipties through the pipe, and then securely through the grommets. The PVC pipe is then attached to eyehooks on the greenhouse. This anchors it on windy days.

The other end is attached the same way to another length of PVC pipe and then secured to the roof line and anchored to eye hooks.

Inside, the temperature has already started dropping from 120 down to 100 degrees, and the light is softer with the heat filtered out.

By the end of the day the temperature has dropped to 80 degrees.

This morning the lettuce was crisp and literally a brighter, deeper shade of green.

The oregano seedlings have started sprouting.

And the pot of oregano literally exploded.

The comfrey added an inch or two, and the leaves are more alert with variations of green.

On the whole, everything just seems to prefer the filtered light, and the warm, but not searing hot temps.

Even the water plants have greened-up. They are probably anxious to get back in the outdoor pond. Hopefully, that will be ready next weekend.
Meanwhile in the outside garden:

Horseradish is back with a vengeance. I use it as an insect deterrant, but it can be easily harvested to make horseradish (just grate the root). But be warned that this is a plant that is almost impossible to get rid of - every piece of root will sprout a new plant. I happen to like it, and don't mind it spreading.

The peas planted in bales a week or so ago are sprouting now, thanks to everyday watering to get them established.

Today we had to mow for the first time this year, and cut down some wild paradise trees that seem to pop up everywhere. Next weekend is the rain barrel system!


  1. Looks like that shade cloth has done the trick for you! Good job! Wish I had a greenhouse -- maybe one of these days... I'm anxious to see how your hay bales do.

  2. Glad the cloth is helping the greenhouse, and plants therein, with the heat! I really can't wait to see your hay bale garden in full "bloom."