Q&A: Starting Seeds


I have trouble with starting seeds and maturing them to plants. If they come up, they stay small and don’t grow past that.

Thank you,

C, Your plants are probably not getting the right fertility. When seeds germinate they have some energy that they live off of for a few days that was stored up in the seed itself, kind of like a chick gets its first few days’ worth of nutrition from the yolk right before hatching. Your seeds are germinating but they aren’t getting fed much after that. Let’s get that fixed.

These are the keys to starting seeds.

  1. Good quality, fresh seeds. Last year’s seeds may not germinate very well compared to newly ordered ones, especially if they were not stored properly. It’s always worth spending a few bucks on a new pack of seeds to make sure. When you get them, write on the packet the date you received them, then store them in a ziplock bag in the freezer.
  2. Good quality potting mix without any fertilizer in it. I use Pro-Mix BX from Chastant Bros. in Lafayette. It comes in a 2.8 cubic foot bag.
  3. Add your own organic fertilizer to your potting mix at seeding time. I use MicroLife 6-2-4 Multipurpose (also available at Chastant Bros). You have to grind it up into a powder. I use a cheap food processor that I keep in my nursery. You could use a mortar and pestle or just your kitchen food processor and wash it afterwards. The rate is 1 oz. MicroLife per 1 gallon Pro-Mix.
  4. Get the temperature right. In general, 70°F is going to be good. I use a germination chamber that I built using an old refrigerator (old but still working). You can just bring your seeds inside and that should be good for most vegetables. If you have a heating mat that would help start summer seeds in late winter (like tomato seeds in February). Here is a page with temperatures and number of days to germination for each crop.

Some other little details

Wet the mix
When you mix up your Pro-Mix it will probably be pretty dry and dusty. Add a little water. Not soaking wet, but just enough to make it not dusty anymore. Peat moss (the main ingredient in Pro-Mix and all potting mixes) doesn’t like to get wet. You have to work the water in by mixing with your hands. Once you get it wet initially it will be much more willing to soak up any water you sprinkle on it later in pots.

Cover Material
It is really helpful to cover your seeds with a thin layer of vermiculite. You can get that at any garden center. This helps keep moisture next to the seed while leaving a path of low resistance for that little seedling to go through when it emerges.

Seed Depth
For seed depth, most seeds can go down about 1/4 in. Make a small hole (I call it a dibble) with your finger or the back end of a pencil or marker. Really big seeds like squash can go deeper. For really tiny seeds like celery and many herbs (think basil or chamomile), don’t make a dibble, just put them right on top of your potting mix and then cover them with vermiculite.

Onions and chives, although pretty small, really need to have that 1/4” depth or more because when they stand up they need a little dirt around the base to hold them up.

Watering in your seeds
Use a water breaker with as many holes as you can get. (Hint: the one at Home Depot is not the one with the most holes.) This will make a nice, gentle shower which will get water to your seeds without splashing them right out of their cells or pots. Dramm makes some good watering products. Turn on your water off to the side, then pass it over your seeds. Never leave the water stream in one place. Always use constant motion, beginning off of one side of the tray and ending by passing up the opposite side. Water once, let it soak in for a few minutes, then water again. Your seeds won’t germinate if they don’t get enough water. Too much water can drain off and shouldn’t be an issue. Too little water might end up disappointing you with low germination rates.