Seed starting time!

All right boys and girls, it's seed starting time! A few people have asked me about starting tomatoes from seed. I turns out tomatoes are one of the easiest plants to start from seed. Here is how I do it.

In the past, I have used this stuff:

Now, I use generic potting soil to start my seeds. Both are perfectly viable methods. Seed starting mix is light and fluffy, and seedlings have an easy time breaking through. It also is sterile, or close to sterile, so you're less likely to have mold-related problems. It also drains really well, so you're less likely to overwet the mix. On the downside, it has almost no nutrients at all. I find that once the seedlings reach a certain size, they start looking sickly and need additional fertilizer. This is a bit of a hassle, but not a huge deal. With generic potting mixes, this nutrient deficiency never happens. They usually come with enough fertilizer to see the seedlings through until you plant them outdoors, but not so much fertilizer that you burn their roots. The biggest issue with these potting mixes is they can have big chunks of wood and pumice, which a seedling won't be able to push through. So you have to be careful that there's only loose, fluffy soil on top of the seeds. In the past, I've filled the bottoms of my cups with potting soil, and covered the tops with seed starting mix. This works great, but you don't need to get that complicated.

Into whichever soil I'm using, I mix Arboreal Mycorhizae (AM):

I'm convinced this is the key to growing giant tomatoes. I used it on all of my tomatoes last year. You can read about it here: http://www.ovgpg.com/documents/articles/ovgpg10.pdf . I add AM when I start the seedlings, when I pot them up, and again when I plant them in the ground to make sure the roots are fully inoculated.

The soil mix should be thoroughly moist, but not wet. You shouldn't be able to squeeze any water out of it. It should be moist and springy, like devil's food cake. I read a technique where a grower would fill an entire flat of cups to the rim with potting mix, then drop the tray 6" onto the ground to knock out any air pockets. I do essentially the same thing. I fill the cup to the rim, then tap it a couple times against my palm to knock the air out, but not compact the soil.

I start my seedlings in 2 1/4" cups that I recycle from vegetable transplants, but you can use just about anything. Yogurt cups, Solo drink cups, pretty much any plastic cup will work. Make sure you drill large holes in the bottoms so they have plenty of drainage.

In each cup, I poke 2 or 3 holes for the seeds. Tomato seeds want to be planted less than 1/4" deep. Too deep, and you risk them not making it to the surface when they sprout. Too shallow, and the surface of the soil could dry out before they germinate. 0.2" is about perfect. I used to use a pencil eraser as a guide, but I found that a plastic pen made cleaner holes.

I drop the seeds one at a time in the holes. To cover the seeds, I either knock the edges of the hole in, or sprinkle some additional potting mix in the hole. I give two or three squirts of plain water from a spray bottle to remove any air pockets, make sure the potting mix is in contact with the seeds, and moisten the seeds. With only a few squirts of water, the excess water will drain into the pot, so the seeds shouldn't get too wet.

A typical germination rate for tomato seeds is 80%, so with 2 seeds per pot, your odds of getting at least one to germinate is 96%. 3 seeds to the pot, and it's better than 99%.

You want the seeds to stay warm and moist until they germinate. There are many ways to keep the soil moist, but if nothing else, here is an easy way using ziplock sandwich bags. You don't need any air holes. And you don't need to add any water until the seedlings emerge. Inside the baggie should be humid enough for condensation to form, and the soil will stay moist.

A warm, dark place is ideal for the first 5 days, but after that, you'll want to move them to a bright south-facing location. As soon as the seedlings emerge, they will reach explosively for the light. If it's not bright enough, they will get long and leggy, and can flop over and die. Ask Farmer McGregor what leggy seedlings look like. 70 to 80 degrees is the ideal temperature range. You probably have some electronics or the top of a fridge at close to the ideal temperature. Under the right conditions, tomato seeds will usually emerge in 5-7 days.

I find that 5-6 weeks is about perfect for starting tomatoes. Much more than that, and they become difficult to work with. Also, the stalks start to toughen, which you don't want. Young stalks will readily grow roots out their sides when they're planted below ground. I usually plant my tomatoes in the garden around the 3rd week of May, so now is the perfect time to start them!