Seed Starting 101

This is one of my favorite times of the gardening year. I’ve had a chance to rest up a bit from heavy-duty gardening chores, and my batteries are recharged. The days are getting longer now, and it’s time to start planning for a new garden. For me it’s a time of year that’s full of hope, energy, and the promise of things to come! Last month I took a little time and planned my 2013 garden, deciding what I want to grow. Then I did an inventory of my leftover seeds, and came up with a list of what I needed to order.

seed starting supplies (click on any image to enlarge)

seed starting supplies (click on any image to enlarge)

I have ordered most of the seeds now, and a few have even started to arrive. I start most of my plants myself from seed, and it is an easy and economical way to get new plants. It can often be the only way to get the specific varieties you want to grow. You can start seeds for most vegetables, flowers and herbs – even trees and shrubs for that matter. A seed is just a plant waiting to happen, and as gardeners all we need to do is create the proper environment for it to grow.

broccoli seedling, with seed shell still attached

broccoli seedling, with seed shell still attached

I’m often asked questions about starting plants from seed. There’s certainly a lot of different ways to go about it, and every gardener has slightly different methods and materials they like to use.  But most of the basics are very similar. A little bit of planning can ensure success with your seed starting, and perhaps head off some of the common problems before they happen. And if you’re new to gardening, there are a few things you want to address even before you open that first seed packet, like the following items:

  • Light – young seedlings need 12-16 hours of light per day. For that you need a bright sunny windowsill (south is best) or fluorescent lights. Seeds and seedlings should be kept 1-2 inches from the lights. Use plant grow bulbs or a combination of 1 cool white and 1 warm white bulb. I use fluorescent lights with an automatic timer set to be on for 14-16 hours per day.
  • Containers -need to be clean and sturdy. Plastic is easy to clean and sterilize, plus it is lightweight and reusable. You can use pots, cell paks, or flats. Other choices include wood flats, peat pots and pellets, and homemade soil blocks. Plastic cups and the bottoms of milk cartons can also be used.
  • Growing medium -needs to be well-drained, light and fine-textured. You can use a commercial mix or make your own. Avoid using soil  straight from the garden, because it’s heavy and can harbor diseases and insects. A commercial mix containing peat moss, vermiculite and perlite works well (I use Pro-mix). Coco coir, which is made from coconut husks, is gaining popularity as an economical and earth-friendly alternative to peat moss for seed starting and growing mixes.
seedlings in 288 cell plug tray

seedlings in 288 cell plug flat

There are also a few other things to research before you start sowing those seeds. Much of the information can be gleaned from the seed packet itself, or from a good gardening book. Johnny’s Selected Seeds catalog has a lot of data on individual seeds and their needs, plus their seed packets are some of the most informative I have ever seen. And “The Vegetable Gardener’s Bible” by Edward C. Smith has good information about each vegetable’s requirements from sowing to growing. Some of the things you need to know include:

  • When to plant – use the seed pack, catalogue or book to help determine the timing.
  • How deep to plant seed/how much to cover. Some seeds need light to germinate, while others need darkness.
  • Temperature needs (hot, warm or cool). Use a heating mat or cable to warm the soil for heat lovers such as tomatoes, peppers and eggplant.
  • Germination time – how long do the seeds take to germinate
  • Seed viability. Seeds typically last from 1 to 5 years depending on species. Store seeds in a cool dry place. You can test viability using a damp paper towel in a ziploc bag.
  • Special considerations – some seeds need to be nicked or soaked, or need a cold treatment before they will germinate.
handful of lettuce seeds

handful of lettuce seeds

Once you’ve done your research, it’s time for the fun part – actually sowing some seeds. Here are a few tips and considerations about the process itself:

  • If using pots or containers, fill with mix to within an inch of the top. This leaves some room for watering later on. Either pre-moisten the mix or water after filling the container but definitely moisten it before seeding. If using small cell packs, fill almost completely with soil.
  • Sow seeds thinly and uniformly (try not to put too many in one spot). The number of seeds depends on the size of the container. Sow several seeds in pots and larger containers (you might sow a dozen or more small seeds in a 4 inch pot), and sow one or two per cell pack, peat pot or soil block. You can thin or cull seedlings later as needed.
  • Cover seeds with seed starting mix, vermiculite or sphagnum moss. For seeds that need light to germinate, don’t cover seed at all. For soil blocks and peat pellets, sow the seed to the proper depth.
  • Water gently or mist. Bottom watering is also good – place container in pan of water. You want to make sure the seed has good contact with the planting medium.
  • Containers or flat may be covered with clear material like plastic wrap or cover to retain moisture and heat. Remove covering as soon as germination is underway. Don’t put covered containers in direct sunlight, or the seedlings will get cooked.
  • Label what you plant. Remember, all tomato seedlings look about the same when they’re coming up!
  • Don’t allow seeds to dry out before germination. Check daily and water as needed.
lettuce seedlings in plug tray

lettuce seedlings in plug flat

Once you’ve got the seedlings up and growing, here are a few considerations to keep them healthy and happy:

  • Keep seedlings in good strong light to keep them short and stocky. Tall, spindly seedlings are a sign they’re not getting enough light. If using fluorescent lights, adjust the distance to keep the growing plants within 2″ of the lights.
  • Maintain a good growing temperature , typically around 70F during the day and 60-65F at night. Check specifics for each plant.
  • Do not over water, water only when needed. Soil should begin to dry out between watering, but never allow seedlings to wilt.
  • Fertilizer – plants will need fertilizing. Begin 2-3 weeks after germination, or when true leaves start to appear. Use half strength or weaker liquid fertilizer every two weeks (I use a fish emulsion and seaweed combination like Neptune’s Harvest)

I know that’s a lot of information to digest, so I’ll be back later on with more information on handling any problems, plus tips on thinning, transplanting, and hardening off seedlings to prepare them for planting. I’ve also put this presentation on my main menu, under “seed starting information”. I hope you this information proves useful to you, and Happy Growing to all you gardeners out there!




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3 Responses to Seed Starting 101

  1. Miss Bougie says:

    Thanks Dave for the wealth of information in this post. I’m new to seeding and I’ll try to follow your advice.

  2. Mary Dunlap says:

    Thank you for your vast knowledge and information! I enjoy your website very much. Thanks for sharing.

  3. Pingback: Seed Starting Setup | Our Happy Acres

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