Seed Starting Pt. 1 – Why Start Seeds?

Those of you who have read my previous posts know that in addition to an avid winemaker, I am a lifelong gardener. In Wisconsin, like many parts of the country, the only way to grow many types of vegetables and flowers is by setting out plants started earlier in the season from cuttings or seeds. I start most of my own plants in a seed starting rack I’ve built in my basement. This series will step you through the basics of starting plants from seed and setting them out into your garden.

So why start your own plants when you can easily buy a garden full just about anywhere? If you grow large quantities of plants you can realize some savings by starting your own. If you save seeds from last year’s garden you don’t have to purchase all of your seeds each season, and seeds kept cool and dry will last for years. I’ve had seeds as old as 10 years that still germinated. I reuse flats and packs as much as possible which not only saves a bit of money, but keeps some of the plastic out of the waste stream.

The range of varieties you can grow increases exponentially when you start your own plants. Garden centers tend to have a limited selection of started plants compared to the choices you have from seed suppliers. I’ll grow a few new types of plants every year and include at least 1 new type of tomato. Many types of tomatoes are available only by seed, and although some of them aren’t as attractive or long keeping, they’re often much more flavorful.

And when you grow your own, you control how the plants are treated. You know exactly what has been applied to the soil and plants and if you’re following organic practices there is no question about those claims.

And of course there’s the satisfaction of coaxing a tiny seed into a beautiful flower or tasty vegetable. Producing food locally is environmentally sound, more energy efficient, and if the economy really takes a dive, well, at least you’ll have something to put on your table.

Seed Starting Pt. 2 – Nice Rack!

The first thing you’ll need when starting seeds is a suitable place to do it. In order to start seed successfully, you must meet the environmental requirements for initial germination and subsequent growth of the plants until they reach the stage when they are ready for transplanting. A well designed rack or other area will meet the needs of correct temperature to start germination, and sufficient light and space to stimulate healthy growth.

This is the rack I’ve built for starting my plants. I start a couple hundred plants each year so this setup will be overkill for most of you, but the concepts are the same regardless of the number of plants you are growing. Seeds need warmth, generally from 60 – 80°F to start germination, however some types of seeds are less tolerant of the high and low temps in that range. I’ve found that an average of 65-75°F is a good general range for a variety of seeds. A means of providing bottom heat to some of your flats warms the soil from below and speeds germination of some types of seeds such as tomatoes and peppers. Good lighting is a must – you can’t have too much light. Plants growing in low intensity light soon become spindly and weak And you need sufficient space for the plants to grow into. Plants that are too crowded have weak stems and misshapen leaves.

My rack is a two-tiered design, with a wood framework, and sides made from foam insulation board. This traps the heat generated by the lighting and provides a proper temperature range for the seeds in my unheated basement. All inside surfaces are lined with a highly reflective mylar material I’ve scavenged from work. If any of you have access to a printing company that uses the Kodak Approval proofing system, this material is a byproduct of that proofing process. Any reflective lining can be used including aluminum foil. I’m sure at least a few of you have had experiences with foil-lined closets and grow lamps. The front of the unit has additional pieces of foam insulation board cut to fit by friction so they can be easily removed for access.

The upper shelf has a gap at either side of the unit to allow for air circulation, and the top is vented to let excess heat escape. My unit is almost too well insulated and I have to be careful not to let temperatures get too high when all of the lights are in use. Keep at least a couple of thermometers in your unit to monitor the temperature in several places.

The upper section has six, four foot 2 bulb florescent fixtures hung from the top by chains that provide for easy height adjustment. Unless you’re growing seeds in a window you will never have light as intense as natural sunlight, so you need to keep your light source as close to the tops of the growing plants as possible making simple height adjustment a must. Some recommend using only special full spectrum “grow light” bulbs, but I’ve found that by using a mixture of warm and cool white bulbs you get the same results for much less expense. The bottom section has two 120W flood fixtures mounted directly on the bottom of the upper shelf. These are the heat sources for the early stages, and they also heat areas of the upper shelf to provide bottom heat for some of my flats. I’ve heard of people using heating pads or cables for supplying bottom heat to smaller containers. Just be sure to keep the heat moderate so you don’t cook your seeds.

Under the legs of the unit are large bolts threaded into T-nuts fastened to the bottoms of the legs, that are used to level the rack. It’s important that the shelves are level so you have even flow when you are watering your containers.

Of course you don’t need to go to this extent if you are just starting a couple of tomato plants, but you still need to provide the same type of environment. A rack in a warm room won’t need to be insulated, and if you have an area next to a window that receives at least a half day of direct sunlight, you won’t need the elaborate lighting. Bottom heat isn’t necessary, but does speed things up. And regardless of where you’re starting your seeds you need to pay close attention to conditions to make sure things don’t get too far from the norm, or your seeds won’t survive.

A good resource for more information is Nancy Bubel’s book "The Seed Starters Handbook", which has become a standard reference for home gardners.

Click here for my previous posts on gardening and winemaking.

Seed Starting Pt. 3 – Seeding In

Once you have a place to start your seeds you of course will need a growing medium and some type of container to put them in. Containers of all kinds are available, and just about anything can be used from milk cartons to egg cartons to purpose-made seeding flats as long as they meet a few criteria. They must be deep enough and sturdy enough to hold 2-3” of growing medium, they must be able to hold up to being wet, and they must provide adequate drainage. I use commercially made plastic seed flats as they are inexpensive, a convenient size, and easy to use and keep clean. Another option is peat pots, which can hold the plant until it’s ready to be set out, eliminating the need for intermediate transplanting, but they aren’t as flexible as using flats and can get costly for large numbers of plants.

It’s important that your containers be clean and free of any contaminants that may spread soil-born diseases to your seedlings. Every spring I wash out my flats and packs in soap and water with a little bleach added to disinfect them. It’s a tedious job, but contributes to a healthy environment for your plants. And by reusing as many of the containers as possible you’re keeping some of the plastic out of the waste stream, so collect those plastic 4 packs your neighbors that garden throw out every year.

The flats I use are paired with a perforated flat nested into a solid-bottomed flat. This provides excellent drainage and contains any water that may drip through the perforated flat. I line the perfed flat with paper towels to keep the soil mix from washing through the holes, making sure none of the paper sticks up above the soil line.

I then fill the flats to about ½” from the top with a soiless seed starting mix, firming well, especially around the edges of the flats. I’ve found these types of mixes to be far preferable to garden or potting soil to start seeds. They are sterile, so they will not spread pathogens to your plants, hold water well, drain well, and have a light body which makes it easy for the seeds to sprout through. If you use plain dirt, you should lighten the body with peat moss, perlite and/or vermeculite so the soil won’t clot and dry hard between waterings, but because of the chances of contamination I don’t recommend using garden soil. You can however sterilize small amounts of dirt by baking, or saturating with boiling water. If your soil mix is quite dry you should water it thoroughly and allow it to drain completely after filling your containers. This will settle it in and prevent dry pockets that can keep seeds from germinating.

Once your containers are ready, it’s time to decide what to put into them. First, read the info on your seed packets carefully. You need to know the recommended planting depth and temperature range the seeds prefer, and how long before setting your plants out you should be starting them. You should group your plantings accordingly, planting seeds that prefer warmer temps such as tomatoes and peppers together, and seeds that like it a little cooler such as broccoli and lettuce in separate containers. I generally start my seeds about 8 weeks before I’m planning on putting them into the garden and flower beds. In my part of the country, you’re better off waiting until Memorial day to transplant warm weather crops such as tomatoes and eggplant. Keep in mind that it’s the soil temperature that’s important – if you plant warm weather crops in cold soil they’ll just sit there and sulk until the ground warms up. I believe that starting your plants too early does more harm than starting them a little late as it’s difficult to give larger plants optimal growing conditions indoors, and smaller plants will quickly come up to size when planted at the right time, so resist the temptation to jump the gun on getting seeds started.

I’ll put 8 evenly spaced rows of seeds in a flat. I always start some extra plants in case of problems and give away what I don’t use, which is why I start an entire flat of tomatoes. Using a marker stake I make a furrow in the flat to the correct depth for the seeds I’m planting. I then place seeds evenly in the furrow, in the case of tomatoes, 10-12 seeds per row. The rows will be thinned later if necessary after the seeds have sprouted. Fresh seed under optimal conditions will have high germination rates so take the age of your seed in consideration when deciding how close to plant the seeds, you may want to sow a little heavier if your seed is old. Lightly press the seeds into the soil, cover and firm well. Be sure to label your rows or containers and/or make a seeding map to keep track of what is planted where.

Once your container is planted, thoroughly and gently water it. Seeding mixes are often very light weight so be careful not to wash out your seeds. Now your containers are ready to go into your plant rack.

When I first put my flats into my rack I have just the bottom tier lights on constantly to warm the rack and provide a couple of warm spots on the upper shelf for bottom heat. I position the tomato and pepper flats over those warm places as they like it and will germinate faster than if no bottom heat is used. Put at least a couple of thermometers in various places to keep track of temperature and to show you variations in different parts of your growing space and place your containers according to the seed’s preference for cooler or warmer temps.

Check your plants every day, and don’t water your containers until the soil on top is starting to dry out. More plants have been killed by overwatering than underwatering; too much moisture promotes mold and “damping off”, a fungal infection that kills seedings. Soon you’ll be rewarded by the appearance of little green shoots. At that time I start to cycle the fluorescent lights in the upper section. I give my plants about 14-15 hours of light per day. Keep the lights as close to the tops of the young plants as possible without touching them and adjust the height regularly. Some seeds are slower and more sporadic when germinating so be patient and don’t give up on your seeds too quickly. As the rows fill in, thin your plants to about 1 to 1 ½” apart. Do this after watering so the roots slip out easily and don’t disturb the neighboring seedlings when pulled.

After all your containers have germinated you will no longer need the bottom heat if you’re using it. It’s a good idea at this time to lower the temperature a bit in your rack if possible as it promotes sturdier growth. Some elaborate setups include small fans to gently jostle the plants which is supposed to toughen them. I start using a water-soluble fertilizer at this point, mixing a mild solution applied with every watering. Soon, true leaves will start to emerge from your plants and when the second set starts to show, it’s time for transplanting into individual packs.

So what plants do I start? Lots of tomatoes: Wayahead, Roma, Carmello (a French main crop variety), Celebrity, Opalka (a favorite paste type of mine) and Sweet 1,000,000 (Cherry). Peppers: Ancho, Kolaska Paprika, Sunbright (a gold bell), Fat ‘n Sassy (a green bell), and Cayenne. Broccoli, Brussels Sprouts, Zucchini, Cucumbers (the long, English type), Lettuce (Grand Rapids leaf and Buttercrunch), Parsley (Moss Curled and Italian Flat Leaf), Basil, Thyme, and Marjoram. For color I have Annual Flax, Violas, Zinnias, Cosmos (Sensation and Sunny), miniature singlet Marigolds, Globe Amaranth, Shasta Daisies, and 2 types of Morning Glories.

In addition I direct seed other veggies and flowers as well as purchase a couple of flats of Impatiens every year. As you can probably tell, I like spending a lot of time outdoors!

Seed Starting Pt. 4 – Potting Up

As your seedlings sprout in your flats, the first greens to appear are the “seed leaves” or cotyledons. They produce food for the plant as it begins to grow true leaves and are usually distinctly different in appearance from the plant’s leaves. If you are starting your seeds in flats, once the second set of true leaves start to appear it’s time to begin potting up – transplanting your seedlings from the flats into individual containers or cells of multi-packs.

(Click here for previous posts in this series)

There are a number of reasons for this. Plants left too long in flats get crowded and compete for light and root space. Long roots intertwine in flats and make it difficult to separate transplants without excessive root damage. Putting plants in individual spaces isolate the roots making the plants easier to remove from the container for final setting out, resulting in less transplant shock. And the process of potting up weeds out smaller and weaker seedlings leaving you with only the best plants for your garden.

Many types of containers can be used for potting up, the most common being the plastic multi-cell pack. I clean and reuse as many of these as I can, discarding them when they split open. Friends and neighbors that buy their garden plants are a great free source for these packs. Many types of containers can be used as long as they have sufficient room for growth, can hold up to being wet, and provide good drainage. For tomatoes and peppers I like to use a bigger container to encourage the plants to develop a larger root ball. Every spring I have the coffee drinkers where I work rinse their 8oz. foam cups and put them in a box for me. These make great individual pots and puts them to use one more time before they’re thrown out. I make sure they’re rinsed well, then using an 8 penny nail I punch 7 holes in the bottom of each for drainage.

For soil I’ll use any of a number of commercial brands and mix it with the soilless seeding mix from the flats as I transplant. Some brands now have fertilizer added which simplifies caring for the plants. Garden soil can be used, but again there is the risk of soil-borne pathogens infecting young plants. If you use your own dirt be sure to lighten it by adding some soilless mix so it won’t dry hard and crack between waterings.

I put my potting soil in a large mixing bowl to make it easy to add soilless mix and fill packs and cups. I’ll fill a pack 1/2 to 2/3s full depending on the size of the root ball on the plant I’m transplanting. Poke a finger in each cell, firming the soil to the bottom and sides and creating a well for the roots.

Now it’s time to start lifting plants from the flat. Pinch off any seedlings that are small, weak, or too close to a better seedling. You’ll be tempted to try to keep every plant, but the effort is often not worth the results. Using a dinner fork, carefully punch around the plant you are ready to move like you might take a piece of sheet cake from a pan. Lift with the fork from underneath, you will lose some roots, but it won’t matter. Remove only as much excess dirt and root as needed to fit into your container – keep the root ball as intact as possible. Place the plant in the well you created in the pack cell and spoon additional dirt around the plant. If you need to support the plant while backfilling, hold the plant by a leaf, Not the stem. If you damage a leaf the plant will probably recover. If you damage the stem, the plant will die. Firm the soil well around the plant so there are no air pockets in the cell, and continue to fill and firm until the soil level is about 1/8” below the cell walls. Don’t fill too full or the water will run into adjacent cells rather than pooling in each cell when you water.

When the pack is filled, place it in a solid tray to catch any water than may drip through, and gently water the plants in. Your plants may droop at first due to transplant shock but will soon recover. Once your tray is filled with repotted plants it’s ready to go back into your rack or growing space. Adjust the height of your lights if needed and check your seedlings daily. Packs can dry out faster than flats and some cells seem to dry more quickly than others so watch each pack carefully and water when the surface is quite dry. Again, overwatering can do more damage than underwatering, so don’t water too frequently. Continue a light fertilizing to keep the nutrients flowing to the plants. This isn’t necessary if you are using potting soil that already has fertilizer added. After a few days you’ll see your plants gaining size rapidly. Keep your lights adjusted so the tops of the plants are kept just below the bulbs.

Maintain your plants until about 1½ to 2 weeks before you plan on setting them into their final locations. At this time you’ll start the process of “hardening off”; acclimating your plants to an outdoor environment.

Happy Potting!

Seed Starting Pt. 5 – Hardening Off

It’s been a cold, wet spring in Wisconsin and I’ve been busy with my land in Missouri, so my garden planting is far from finished. But that’s given the plants started indoors ample time for hardening off in preparation for setting into their final destination.

In the Spring, your skin needs time to acclimate to being exposed to bright sunlight, and your plants do too. Getting plants accustomed to outdoor conditions is called hardening off, and it’s very important to follow this step or all of your efforts getting your plants started will be for naught.

(Click here for previous posts in this series)

When you first bring your plants outdoors they need to be placed in a location sheltered from the wind, and exposed to only an hour or two of direct sunlight, preferably morning or evening sun. Too much sun too quickly will result in light patches on the leaves of the plants known as sunscald, the plant equivalent of a sunburn. Badly scalded leaves will die and the plant will struggle to thrive. But just as gradually increasing your skin’s exposure to UV rays results in a tan that can withstand full sun without burning, so your plants will toughen up over a period of days until they can safely be exposed to a full day of sunlight.

Watch the weather forecast during the hardening off period for potential frosts or high winds that can damage your plants and temporarily move them to a more sheltered location as needed. Keep them well watered as they will dry out more quickly when outdoors and can easily suffer wind damage if wilted. Increase the exposure time every couple of days, and within a week to 10 days your plants will be ready to handle the outdoor environment.

Seed Starting Pt. 6 – Setting Out

Due to circumstances beyond our control, this series has been on hiatus for a while. The flooding in the Midwest included the river behind my house, and while fortunately, I had no major water problems in my home, my backyard was a soggy mess. Even after the water receded and a week of dry weather, the ground was still too wet to work. The maple seeds however, found the environment much to their liking.

(Click here for previous posts in this series)

This is what my garden normally looks like by this time of year.

I’ve managed to keep my transplants alive, but they were getting much too large and beat up by the wind, so yesterday I decided they had to go in the ground regardless of the soil conditions.

After your plants have been thoroughly hardened off and the temperature and soil conditions are right, it’s time to set them out in the garden. Tender plants need to be set out after all danger of frost has passed in your area. There are ways you can protect warm weather transplants such as tomatoes from cold if you want to get an early start, including row covers, and water-filled jackets that wrap around a plant to hold warmth, but if the soil hasn’t warmed sufficiently the plants will sulk in the cold dirt and won’t take off. I have used some of these tricks on just a couple of plants some years just to get a few extra early ripe tomatoes, but wouldn’t bother for a large number of plants.

The soil needs to be moderately dry – too much moisture in the soil will result in clumping when it’s worked and you’ll end up with hard lumps of soil when it dries, making it difficult for the roots to penetrate. The old rule of thumb is to take a handful of soil from just below the surface and squeeze it into a ball. Press on the lump with a finger, and if the soil is dry enough it will readily crumble.

Plan to allow enough space for plants to grow so they don’t compete for light and have sufficient air circulation which inhibits disease. I plant tomatoes and peppers in wide rows with a double row of plants planted in a zig-zag pattern. Rows should be no wider than twice your arm’s length, so you can easily reach all parts of the row from one side or the other.

Loosen the soil well at each planting location and dig your holes. Depth of planting will depend on the type of plant and its size. Plants that grow from a central crown such as parsley should be planted at the same depth as they were in their original container. Many plants like tomatoes that grow from a single stem can be planted deeper if the transplant has gotten taller than it should have before transplanting. Tomatoes and peppers will sprout additional roots from the lower portion of the buried stem.

Gently remove the plant from its temporary container and in the case of gangly tomatoes, pinch off a couple of the lower leaves, and place into the planting hole. Backfill with soil, firming around the root ball and stem to ensure there are no air pockets around the roots. I like to form a shallow depression around the new transplants to hold water. Water in well and if you are growing several varieties of one type of plant, be sure to mark the plant or make a map of your rows.

Allow a couple of days for the plants to recover from any transplant shock, and get ready for the burst of growth that will soon follow. In the case of tomatoes, after a week, trim off any leaves that touch the ground as vegetation against wet ground is a ready means of infection from soil borne disease. I use homebuilt tomato cages I’ve build from concrete rewire for supporting my plants. They’re cheap and easy to make so I’ll have a post up soon on how to make them.