Starting your garden plants from seeds indoors can be an enjoyable project for any gardener. While it’s possible to grow a productive vegetable garden by purchasing plants that were already started, you’ll have a much greater range of possibilities by starting your own from seeds indoors.
Buying seeds is relatively inexpensive and you’ll be able to choose from an extensive array of garden favorites in a wider variety of sizes, colors and growth habits as seeds, rather than started plants as well. It will allow you to have fun experimenting and harvest the edibles you like the best over a longer period of time, by planting varieties that mature at different times.
Plus, when you start your own seeds, you know for sure that those plants have been raised organically from the very beginning, and you don’t have to wait for that warm weather to arrive before getting your hands in the dirt.
Now that you know the reasons behind it, here’s some tips to help you get started.
1. Buying your seeds…
You’ll find there are many different options for purchasing your seeds, from nurseries and garden centers to your local building supply store, mail order catalogs, and websites. Prices can vary significantly, with the newest hybrids typically commanding higher prices, as well as seeds of unusual or rare plants and certified organic seeds.
Name brand seed packets typically include detailed planting and care information, though less expensive “off brands” (provided the names are the same) generally provide the same quality as the percentage of germination and seed purity is government regulated. Many companies sell various sizes of seed packets, from “mini-packs,” with as little as 10 seeds, to seeds by the pound. When you purchase smaller quantities, it will cost more per seed, but you don’t want to buy more seeds than you’ll plant within the next two to three years at most as each one contains a plant embryo that has to stay alive until it can germinate. That means, the fresher the seed is, the greater the odds that all of the seeds will still be usable. As time passes, fewer of the seeds will germinate.
If you end up with leftover seeds, you can save them for the following year, just be sure to store them in an airtight container in a cool spot. The refrigerator is an ideal place, but you may want to add a packet of silica gel to the container to keep the humidity level down.
When searching through those catalogs and websites, look for these labels that are commonly used to identify the characteristics of the seeds:
“U” = untreated. That means the seeds were produced without using any synthetic herbicides, pesticides or synthetic fertilizers.
“O” = organic. These seeds were produced from parent plants that were organically grown.
“OP” = open-pollinated. This refers to seeds that are capable of reproducing themselves. They can be dried and saved over the winter season, and used for planting the following season.
“H” = heritage or heirloom. These types of seeds are saved and passed down through the generations by those who want to preserve their genetic diversity, as well as the unique traits of the plant they produce. They’re most commonly found through local seed exchanges, though some of the smaller seed companies may offer them as well.
2. Choosing the right plants…
Some plants just lend themselves better to germinating at home than others. Some of the easiest to grow tend to be cabbage, broccoli, cauliflower, lettuce, tomatoes, peppers, chives, leeks, basil and Brussels sprouts. The classics for indoor starting are the crops that are typically grown singly and take a fairly long time to go from seed to dinner plate companions, such as winter squash, eggplant, peppers, tomatoes, and cucumbers. Zucchini grows incredibly well, but their growth is so rapid that most people just plant the seeds outdoors when the soil has warmed up, though they can be started inside too.
When it comes to flowers, some of the most reliable annuals include marigolds, cosmos, and zinnias. The best perennials are typically columbines, Shasta daisies, and hollyhocks.
If this is your first experience starting seeds, avoid taking on too much – start a couple of dozen plants or so in just three or four varieties while you get familiar with the process. Different plants have different requirements, so carefully read the seed packet to learn how many weeks each one will take to get ready indoors before your area’s last frost date. You’ll notice that many seed packets include a number of days to mature, like “65 days,” or “80 days.” Be sure that you understand whether that refers to days from sowing the seed, or days from transplanting outdoors as it typically varies from vegetable to vegetable.
3. The growing medium…
Seeds are very delicate, and from the day they germinate, they face a host of challenges, from bacteria in the soil, water, and air to fungi. The fewer hurdles they have to overcome, the better they’ll grow, which is why your seed-starting mix is so important. For the best chance of success, they should be started in a fresh, sterile seed-starting mix that’s light and fluffy, allowing it to hold just the right amount of moisture. If the growing medium is too wet or not sterile, disease is much more likely. And, if it’s too sticky or too heavy, those fine new roots will be unable to push through.
A quality seed-starting mix is formulated in a way that’s meant to discourage common soilborne pathogens that cause seedlings to rot, and it will easily retain both air and water.
You can use bagged seed-starting mix, purchase coir (coconut husk fibers) or compressed pellets of peat that will expand when wet. As seeds contain the nutrients the seedlings require, fertilizer isn’t important when looking for a quality seed-starting mix. Another option is to make your own by mixing equal parts of peat, perlite and vermiculite. Add a quarter teaspoon of lime to each gallon of mix to neutralize the acidity in the peat.
4. Selecting the best containers…
Your seeds will need to be started in small, individual containers. Cell-packs or pots can be reused, but it’s essential to clean and sterilize them thoroughly in a solution of 1 part bleach to 9 parts water. Be sure they have good drainage holes so excess water can drain away, and get a shallow waterproof tray that will hold them.
Small paper cups with holes punched in the bottom work well as they can disappear right into your compost after using them. Planting cups rolled from newspaper and cardboard planting “boxes” that are made by re-folding and stapling discarded food boxes will do the same. There are many different types of fiber pots made from organic materials, like shredded wood, cow manure, and peat. Fiber or paper pots that break down in the soil are great for raising seedlings that don’t transplant well, like cucumbers and squash. If you’re trying to decide between clay, plastic or paper containers for starting your seeds, pass on the clay containers as they don’t retain moisture as consistently. Recycled plastic containers, such as empty yogurt cups, work well too as long as holes are poked in the bottom to allow for drainage.
It’s best to use divided containers with just a single seedling in each, instead of filling up a larger container with seed-starting mix and sowing many seeds, as the roots tend to grow into each other, and are much more prone to injury during transplanting.
Seed-starting kits are readily available and can be very helpful as they usually include an attached set of good-sized containers, a tray to set them on and a clear lid to hold in humidity during the early stages. Like this one on Amazon.
No matter which containers you choose, the No. 1 concern is that they are clean and completely free of pathogens.
5. Sowing your seeds…
Sow your fresh seeds individually into each container according to the package directions. If you are unsure about seeding depth, a good rule of thumb is to plant a seed four times as deep as its width. Some needs must have light to germinate, so you should cover them using a thin layer of fine vermiculite that’s porous enough to allow light to penetrate, yet will keep your starting mix moist enough to encourage the seeds to germinate. For seeds that require darkness to germinate, place the cell packs in dark plastic bags, or keep them covered using a few layers of newspaper until they sprout.
6. Where to start your seeds…
Avoid placing your seeds in a windowsill as they tend to get cold at night and then very hot during the day. Seeds need consistently warm soil in order to germinate and produce strong roots. If the soil is too cool, it can result in disease and death. Too much heat can completely dry out your seed-starting mix, with the same results. Another concern is water damage to the woodwork.
Choose a location that will be safe from excess heat or cold drafts, as well as pets, heavy traffic, small children, etc. You want a spot where spills of water or the potting mix won’t be a problem either. Typically, room temperatures above 60 degrees Fahrenheit are adequate, provided bottom heat is provided, which means your basement may be a good place for starting seeds.
7. Provide airflow and drainage…
A fungal infection, or damping off as it’s often referred to, is generally caused by poor air circulation and too much moisture. To prevent this, you can cover your seeds with the planting mix and tamp them down by spreading a thin layer of 50 percent starter chicken grit and 50 percent milled sphagnum over the surface to keep the soil around the growing shoots dry and ensure an inhospitable environment for pathogens. Placing a small fan near your seedlings will promote good air circulation. Keep it on the low setting and direct the airflow to blow across the containers at soil level, where the air can become stagnant.
While your seeds don’t require light in the germination stage, when the embryo of the plant emerges from the seed, it will need gentle warmth. Too much heat is a problem, however. You can provide what they need by setting your containers on top of a dryer, or several inches above a radiator. There are also special heating mats sold specifically for this purpose as well. When the sprouts are about a half-inch tall, move your plants to a place they’ll get the light they need in a cooler environment between 60 and 70 degrees, or your typical comfortable room temperature.
9. Keep moisture level constant…
As seeds are very sensitive to both under- and over-watering, it’s essential to avoid either extreme. You can help keep moisture levels constant by covering your containers with a loosely fastened plastic bag, or the cover from your starter kit if you purchased one. You’ll still need to check your seeds every day for germination and moisture, however. If your container needs to be rehydrated, place it in a basin with about 2 to 3 inches of warm water, allowing the planting medium to wick moisture from the bottom. If the surface has dried, use a spray bottle to water it gently without washing the potting mix out of the container, or add a little water to the tray and allow it to move up into the mix. Whichever method you use, be sure to drain any excess water that remains or accumulates in the tray in order to keep those roots healthy.
10. Getting your seeds acclimated to the sunlight
When starting your plants indoors, they won’t have had any exposure to the elements, including full sun, temperatures that fluctuate greatly and wind. If they don’t gradually become accustomed to the outdoors using a process known as “hardening off,” their leaves may become scorched – and they could even wilt or die.
The best way to do this is to acclimate them over several days, by placing them in direct sunlight only in the morning during the first day, and gradually increasing the spend they spend outside by a few hours every day until they’re strong enough to be transplanted.