Direct Seeding is the most straightforward method of plant propagation. Just put a seed in the ground and watch it grow! Follow these guidelines for success:
- Store your seeds properly. Seeds require both cool temperatures and low humidity to maintain their viability. When at a site, keep seeds in the shade; do not store them in a hot vehicle. At the end of the day, always return seeds to a sealed plastic bag in the fridge.
- Before planting, use a garden fork to loosen the soil to a depth of 8 inches. Do not flip the soil though—it will hurt both the microbes in the soil and your back. Then, use a garden claw to incorporate about half an inch of compost into the top 2 inches of soil. At this time, remove any weeds. Finally, break up any large clods of soil with a bow rake while at the same time leveling the soil in the bed.
If you have recently tilled under a cover crop, wait at least two weeks for it to decompose before direct seeding. Seeds may rot in the ground if planted earlier.
- Plant at the correct spacing and depth. Most seeds should be planted at a depth equaling twice the diameter of the seed. Corn and wheat, an exception, should be planted 1” deep.
For small seeds like lettuce, carrots, and turnips, work the soil into a fine tilth with a hoe or rake. Create shallow furrows, plant densely, and cover the seeds with a light layer of soil (leaving a slight depression inside the furrow).
- Tamp the soil down gently with your hand after planting to remove large air pockets.
- Water well. Newly planted seeds need water about every other day. Small seeds planted in the summer (e.g. carrots) should be watered regularly until they emerge in order to prevent a crust from forming on the soil. If this crust forms, it can kill seeds before they sprout.
If you planted densely, remember to thin the seedlings to the proper spacing once they emerge.
Broadcasting is a method of direct seeding many seeds at once. Prepare the bed in the same manner described above in Step 2, then scatter the seeds (e.g. clover or field peas & oats) evenly over the bed. Scuffle the soil with a bow rake to cover the seeds and tamp the soil with the back of a spading shovel. Water gently.
The row seeder works by creating a small furrow, into which your seeds are dropped. The attached chain covers the furrow with soil, while the back wheel lightly tamps the soil.
- Prepare the soil in the manner described above in Step 2. You may want to mark where each row begins and ends to guide your planting.
- Adjust the seeder to the proper depth. On uneven ground, test the seeder before planting by running it over the garden bed a few times and observing the depth of the furrow it creates.
- Select the appropriate seed plate for the seed you are planting and insert it into the seeder. Then, pour a few handfuls of seed into the seed reservoir.
- Run the seeder down the row once. Then, turn around and repeat over the same row in order to assure adequate seeding. If you are planting lettuce or carrots, you may need to turn around yet again and make a third pass.
- Move the seeder to the next row and repeat the process.
- Water well and wait patiently.
Transplanting is the process of placing a seedling into the garden soil where it will mature. Follow these steps for transplanting success:
- Harden off your seedlings before transplanting them. About a week before transplanting, place them in a shady spot during the day and, if temps are forecast at 40° or below, bring them back inside at night. Each day, gradually increase the amount of direct sun they get. During this process, reduce the amount of water given to seedlings. Allow the soil to dry out a bit, but don’t allow the seedlings to wilt.
- Select the strongest and healthiest seedlings for transplanting. If more than one seed germinated in the pot, use scissors to cut off the most spindly seedlings at the base of the stem. Do not pull unwanted seedlings out by their roots, as this disturbs the soil around your soon-to-be-transplanted seedling.
- Water the seedlings until their potting soil is completely saturated.
- Prepare the bed by using a garden fork to aerate the soil to a depth of at least 8”. Then, use a garden claw to loosen the top few inches. Remove all weeds. If you recently tilled under any cover crop, let it decompose at least 1 week before transplanting.
- Dig holes, properly spaced, just to the depth of the pot. The hole should not be so shallow that some of the seedling’s potting soil extends up out of the garden bed but neither should it be so deep that part of the seedling’s stem is buried. Place a handful of compost or organic fertilizer such as Revita in the hole. Tomatoes and Ground Cherries can be planted more deeply. They develop adventitious roots along the lower portion of their stems.
- Place your seedling in the hole. If your seedlings are in newspaper pots or another type of biodegradable pot, you do not need to remove them from the pot before transplanting. You should, however, rip off any portion of the pot that extends above the potting soil line. If any portion of the pot is exposed to the sun after transplanting, it will wick valuable moisture away from the roots. If the seedling is in a hard-sided pot, turn the pot on its side and rest the stem between two of your fingers. Press on the sides of the pot while turning it upside down to release the seeding into your hand. Try to keep as much soil around the roots as possible.
- Fill the hole with loose soil, pressing down firmly but gently with your hands (not a trowel) to remove any air pockets around the roots.
- Water newly transplanted seedlings with a light nutrient “tea” to help them deal with transplant shock. Tea made from compost or worm castings is ideal. A mixture of diluted liquid fish and liquid seaweed can also be used.
Division is the process of taking a part of an existing plant and replanting it somewhere else. The new plant will have exactly the same DNA as its parent plant, even though it’s a separate plant! Here are the plants that we typically divide:
- Garlic: separate the cloves from the head. Do not remove “skin” from cloves. Replant garlic cloves 1” deep, 6” apart in late October/early November.
- Tulip: after leaves have yellowed, dig up tulip bulbs and separate them. Replant each new bulb 6” deep, 6” apart at same time as garlic.
- Chives: in September, use a spading shovel to divide large clumps of chives into several smaller clumps. Transplant to a new site, or give them away!
- In technical plant propagation parlance, the practice of separating out and replanting the following plant parts is not usually called division, but there isn’t a widely accepted name for the practice, so it’s listed here:
- Potato: after the above-ground portion of the plant dies back (but before the first frost) dig up the potato tubers and store in a cool, dark place. The following April you will notice that the “eyes” have begun to sprout. Replant the tubers at least 6” deep, 18” apart.
- Raspberry: Raspberry plants send out runners (which we call suckers). These runners are essentially new plants, even though still attached to the parent plant by an umbilical cord. Look for them in April and dig them out of the ground, cutting that umbilical cord. Leave some soil around their fragile roots and transplant as soon as possible at least 18” apart.
- Mint: before it flowers in the spring, dig the mint runners out of the ground and replant them in a new location. Mint spreads like wildfire, so either keep beating it back by hand or plant it in a container.
Taking a cutting is a little bit like the process of starting seeds. You take something from a plant, give it the ideal conditions to establish itself (especially its root system), and then plant it into the garden. The most common plant we take a cutting from is the Sweet Potato. Follow these steps:
- In late April/early May, suspend a sweet potato in a jar of water so that about half of it is submerged. It will begin to grow little sprouts, called slips, out of its eyes.
- After about 4 weeks, when they have reached 4-6 inches in length, gently remove the slips and lay the bottom half of them in a shallow dish of water. Over the course of a week or so, they will develop a root system.
- Transplant these rooted slips into the garden 18” apart. Plant them deep enough that all of the roots are beneath the soil level.
- Water well.
- Layering and Grafting are two other common plant propagation techniques (though we don’t commonly use them in our school garden programming). The process is similar to taking a cutting except that a little more work is necessary to establish a root system.
- In the case of layering, a branch from a tree is bent to the ground and then back up (in a U shape). The curve of the U is buried a foot or so underground to encourage the branch to grow roots. It is still being nourished by the parent tree while it is growing roots, so the success rate is often high. After the roots have grown, cut the rooted branch from the tree and replant it.
- With grafting, a cutting is taken from a branch, but that cutting is not expected to grow its own roots. Instead, it is grafted on to some other rootstock (of the same species). If all goes according to plan, the tissue between the rootstock and the cutting melds, and it becomes one plant. This is the most common method used for propagating apple trees.
Download a printable PDF: Plant Propagation