12 weeks to last frost

I hesitate to start a post with a title like this--it suggests I'll have a series.  It could happen!? In fact, I've already split this into two posts, so I could start with a general overview of seed starting.



In Madison, our average last spring frost occurs right around mid-May.  Frost dates are funny little statistics.  I found a good map of Wisconsin climate data here, at our extension office.  If you want to get all weather-nerdy (as I do) you can find charts with the percentage chances by date.  For instance, after May 10th, there is a 50% chance of frost, and after the 27th, there is a 97% chance we will not have below freezing weather.  Cool, right? 

If you're not in Wisconsin, you can do a quick google search for your frost dates by zip code, but check a few sources, I found a lots of variations between commercial sites.  Look for USDA data, and compare it to your own observations about your local micro-climate.  My little protected south-facing yard warms up pretty fast, so I tend to trust the slightly earlier dates.  If you've gardened for a while, look back at your notes from previous years.  Last year?  We had frost right up to May 12th, and the way things are going I think this spring will be a slow start too.

At the beginning of the year I create a basic planting schedule every two weeks from now until May 15th, with notes on the types of plants that are ready to start. First up:  alliums and slow-growing herbs like parsley and cutting celery.  Next come the brassicas, who can go outside bit earlier, along with the eggplants and peppers that need a long running start.  Finally, in mid- to late-March, I start tomatoes.   These schedules don't have to be perfectly followed to the letter, and don't worry if you run a little later than your plans, I find it's much better to have young plants in fine weather, than unhappy overgrown plants waiting out the last cold spell. Most seed starting recommendations have a range, and there is plenty of flexibility.


So, a few very basic overview details on starting your own seeds--I'll be more specific in later posts.  I use a very basic setup:  traditional flats and cell inserts (plastic), and a purchased seed starting media.  If your preference is homemade mix and soil blocks, even better.  Use what you like! 


I also wash, reuse and re-purpose miscellaneous pots for many years.  There is some concern regarding transmitting disease but I have not yet had a problem. 

My light setup is a utility shelf with regular shop lights stolen from the basement where they are used the rest of the year.  I try to have one warm and one cool bulb in each fixture, and am slowly investing in gro-lux bulbs (one for each).  Once sprouted, I have flats as close to the light as possible, and I rotate around as needed to keep similar sized seedlings together. With a simple 2-bulb fixture, I do end up rotating things a bit for even growth.  Some might find this tedious but for me, spring sets are all about puttering.

I also employ the use of my cold frame A LOT.  As soon as the afternoons are sunny and above freezing, I haul out the four most mature flats to the picnic table.  As much as I think regular fluorescent lights are fine, the real deal is of course better, and it makes more room inside for younger sets.  I get very sturdy starts with the cold frame, plus most of the time the temperature inside is a lot warmer than we keep our house. Again, you need to carry things in and out when there are cold nights, and keep an eye out for spiking temperatures or damaging wind. A little breeze, however, is good for strong stems.

Now that I have the hoop house, I use it as a giant cold frame too, but it's a lot farther from the house, which means many trips (including a flight of stairs).  It's better for hardier sets like alliums, and later in the season for hardening things off. 

Just a last note: this is my setup which has evolved over 10-15 years--it started out WAY smaller--one or two lights, a few flats, and lots of practice.  I find it fun, I know not everybody has the time or space (or inclination), and buying sets is a perfectly fine option.  But if you are yearning to have something green indoors to remind you that spring is indeed coming: don't worry about having the perfect equipment to start with, and go for it!