Tuesday, August 9, 2011
I noticed in Johnny's Seed catalog last week that they have little graphs for each vegetable variety that show what soil temperatures are best for germinating seeds. I have never seen them before. I do not know if they are new or I am just unobservant.
This is extremely useful information, especially this time of year when seeds for fall crops need to be sown and it is still hotter than the hinges of hell. Take beets. In the past i have sown beets in the ground in mid to late September. I rarely got beets until the following spring because they ran out of warm growing days before the roots formed. Well, Johnny's little graph tells me that they germinate best when the soil temperature is 86º. That is quite warm. I went out a little earlier with my instant read meat thermometer and did some research. Of course i have no idea how accurate my thermometer is so take this with a grain of salt (whatever that is supposed to mean). Bare soil in the sun was about 87º. Soil under wheat straw mulch in the sun was about 82º. Soil under the lima bean trellis where the sun never shines directly was about 77º. Clearly there are differences depending on the environmental conditions. So the conclusion is that I need to plant my beets this week! The seed package says they will be ready in 55 days so i should have beets by mid to late October. Yiippeee! I had planned on planting carrots this week but carrots ideal soil germination temperature is 77º so i will wait a while before planting them.
Today i planted several different brassicas in flats. Broccoli, collards, mustard, kale, napa cabbage. Self-seeded mustard came up in the garden several weeks ago so I know it will germinate fine. According to Johnny's graph, and my personal experience, broccoli likes cooler soil. Collards, napa cabbage and kale like it hot. I set up some shade cloth to provide some shade for the flats. They will germinate in 3 days then i will remove the shade cloth and watch them grow.
2 weeks ago i seeded arugula in the ground. It is up and growing well in a bed partially shaded by other tall plants. Komatsuna 'Summerfest' i seeded last week and it is up and doing well. Tokyo Bekana greens and Tokyo market turnips that is sowed on Sunday germinated last evening. That was quick.
Apparently there is a worldwide shortage of Hakurei Turnip seeds. I cannot find a source now. Johnny's rep told me it would be late this year before they would have any. If anyone knows of a source for it please share with me.