There are several reasons to transplant instead of direct seed. Transplanting allows close environmental management during the first few weeks, when plants are most delicate. Soil nutrition, texture, and composition can be monitored and manipulated on a micro level, as opposed to amending an entire planting bed. Plants can be started earlier using greenhouses and heating mats, then planted outdoors with a significant head start when the conditions permit. Four Season Tools offers several products that make transplanting easy and efficient. Soil blockers, potting mixes, heat mats, and hand waterers ensure that your seedlings will be happy and healthy at the beginnings of their lives.
Benefits of Soil Blocks
Four Season Tools recommends using soil blocks for on-farm seeding. There are several reasons to use soil blocks instead of plastic containers:
- Compressed soil provides a nutrient dense medium for plant growth
- Eliminates shock associated with other types of transplanting
- Eliminates root circling and air-prunes roots, creating a neat, confined root system
- Promotes excellent air circulation
- Allows for more efficient use of space
- Reduces plastic consumption
Soil Block Options
Soil blockers can come in hand-held or stand-up types in a variety of sizes, allowing more or fewer blocks to made at a time. Blockers are designed to be used with each other, using inserts that accommodate smaller blocks. Fore example, peppers may initially be planted in 3/4-inch mini-blocks and potted on into 2-inch blocks. They are then planted into the field or high tunnel. The following sizes are available:
- 3/4-inch mini blocks with dibble
- 1.5-inch blocks with dibble
- 2-inch blocks with dibble
- 2-inch blocks with square insert for mini blocks
- 3-inch blocks with square insert for mini blocks
- 4-inch blocks with square insert for 2-inch blocks
Soil blocks are simple to use, requiring only a soil blocker, water, and potting mix. Potting mix and water are combined to create a mixture of proper consistency at which point it is packed into the soil blocker and transfered to a surface as blocks. Much research has been done into what premixed potting soil mixes are appropriate for usage with soil blocks. Some companies that we recommend are:
- Cowsmo Compost - Cochrane, WI
- Johnny's Selected Seeds - Winslow, ME
- Purple Cow Organics - Verona & Oconomowoc, WI
- Vermont Compost - Montpelier, VT
If you have had success with other mixes, feel free to contact us. We would like this site to serve as a reference for other growers and appreciate your experiences and knowledge.
Heat Mats and Watering
Germinating seeds require specific temperature and moisture levels. Temperature can be managed using season-extending materials such as floating row cover or greenhouse plastic, as well as germination heat mats. Soil blocks on heat mats are kept at a ideal temperature by conductive heating from the surface of the mat. A controller monitors and regulates soil temperature automatically and can be set at a specific temperature depending on the requirements of a give plant type.
Hand waterers featuring different water pressures can be used for transplants of varying ages. Mini-blocks with germinating seeds require low-impact watering options, such as misting heads, to prevent seeds from being washed off the blocks. Higher volume watering heads are appropriate for seedlings in larger blocks, as they provide quick, effective watering. Overhead irrigation systems can also be installed to maintain adequate moisture levels for transplants.