Starting Seedlings: Equipment and Supplies (Part 3)

(Continued from the previous post)


5) Pots or Containers: Some big-box stores sell plastic cell-packs and trays these days. You can also find biodegradable peat pots and coconut husk pots. If none of these options are available, you can always save your cell packs from previously purchased plants, or ask friends if they have any laying around. If you reuse cell packs or pots, make sure to disinfect them before use by submerging in a tub of water and bleach (and scrub away any clumps of dirt where germs may be hiding).

If you simply cannot find cell packs or pots, you can use plastic drinking cups or leftover food containers (sour cream, cottage cheese, yogurt, etc) as long as you cut a drainage hole in each container. My first year seed starting was done entirely in plastic drinking cups. It took forever to cut all the drainage holes and the cups tended to topple over domino-style with the slightest bump, but it worked out in the end. I do not recommend using paper cups, however, because they may get moldy, tear, and collapse quite quickly.

Plastic drinking cups and peat pots are both options for sowing seeds.

Cut-in-half juice boxes work just fine for growing seedlings.

6) Trays: You will be watering your plants once or twice a day. Unless you are growing in a greenhouse, where the excess water naturally drains away, you will need to put trays under your pots. This will prevent water from spilling onto your furniture or floor. If you use trays, just make sure your plants aren't left sitting in water for extended periods of time!

7) Growing Media (Soil): Seedlings are generally started in a soilless growing media (and then later transplanted to potting soil). While this mix looks deceivingly like soil, there isn't actually any soil in it. Soilless seed starting mixes usually contain a combination of peat, vermiculite, perlite, moss, or coconut coir.

The advantages of soilless mixes are that the media is:

1. Relatively sterile- so there are no soil borne bacteria, fungi, or pathogens to compete with your baby plants
2. Very fine and lightweight- so baby roots can push through the media easily
3. Freely draining- so plants don't become waterlogged and develop issues such as damping off (more on this later)

Soilless mix can be found at some big-box stores and hardware stores. It is usually sold in small bags between 4 and 10 dry quarts (I think I used about 80 quarts last year). If you can't find seed starting mix, you can either make some yourself or use regular potting mix (get something good quality, and it should still work). Due to the sheer quantity of seed starting mix that I go through each year, in 2009 I attempted to make my own mix. It wasn't a total disaster, but it wasn't too great either. The recipe I used included peat, vermiculite, and perlite, but I think my peat was too acidic and not fine enough. Certain species of plants really struggled in my homemade mix, while others (like the always easy-to-grow tomato) did just fine.


If you want less mess, you can also buy compressed peat pellets that expand in water. One seed is sown in each expanded pellet and the whole unit can be planted outdoors when the time comes.

Just a note: If you can't find seed starting mix in your area, you probably aren't going to find the ingredients to make your own mix either.

8) Heating Mat: Electric seed starting mats can be purchased at some big-box stores, or online through most seed companies. These plastic coated mats are waterproof and help raise the soil temperature 10 to 20 ºF above ambient temperature. Increasing the soil temperature will hasten germination and early development of the seedling. This can be especially helpful for germination of warm weather crops including tomato, tomatillo, pepper, squash, pumpkin, and cucumber. I just got my first heating mat this year, so I can't yet vouch for it's effectiveness. Considering that I've successfully grown the above mentioned crops without a heating mat, I would consider this piece of equipment to be optional.