Gardeners everywhere love starting their plants from seeds — it not only saves money, but also allows the gardener to connect to the entire life cycle of their plants. But seeds need a particular set of conditions in order to sprout well, so anything that makes that process easier and more foolproof is enthusiastically welcomed. Like propagation mats, for example — these under-the-tray mats help your seeds germinate more quickly, with a higher success rate and faster growth. Here’s how to use them.
- Plant your seed trays. Whether you are starting seeds or rooting cuttings, start with clean seed trays and sterile growing medium. Use soil that is specifically created for propagation, never regular potting soil or garden soil. This type of soil is loose and drains well.
- Cover the trays. Seeds need moisture and consistent humidity to germinate, or sprout. Many seed trays come with their own clear plastic covers, or you can use plastic wrap over the top of the tray. These covers keep the humidity level high and keep the soil from dying out — the death knell for tender seedlings. Remove the cover once the seeds sprout.
- Place trays on propagation mat. Purchase a mat that is created specifically for seed propagation, and never use a household heating pad. Heating pads are not intended for any gardening purpose, and could actually cause injury or spark a fire. Propagation mats are available here. Make sure you are aware of the size of your mat so that it suits your purposes. Place your seed trays on the mat(s) in a location that provides bright yet indirect light.
- Regulate temperature. Some propagation mats come with controllers, but if yours doesn’t, it pays to purchase one. Seedlings germinate most quickly when kept at a temperature between 70 and 75 degrees, and controllers allow you to regulate the temperature of the mat more closely. This difference between the air temperature and the soil temperature allows the plant to develop a good root system rather than fast leaf production, which will in turn lead to much healthier plants. If the room where you are propagating heats up significantly during the day, be sure to lower the temperature on the mat accordingly. Although seedlings need bottom heat to get going, temperatures that are too high will quickly kill them. Propagation mats typically increase the soil temperature by 10-20 degrees, so take this into account when making any adjustments to heat in either in the room or with the mat.
- Use caution when watering. Some propagation mats are waterproof, but some are not. If yours isn’t, remove your seed trays before watering or misting them, because the water could damage the mat or thermostat. Aim to have consistently moist soil that does not dry out, but avoid keeping the soil too wet. Soggy soil will rot out seedlings very quickly. Be sure the bottom of the tray is dry before replacing on top of the propagation mat. The increased heat from the mat can more quickly dry out your soil, so it’s important to consistently observe your seedlings’ soil moisture and be prepared to lightly water every day if necessary.
- Maintain your mats. If you take the time to invest in propagation mats, it pays to take care of them properly so you will have years of use. Aside from keeping it dry if it’s not waterproof, store it flat without folding it, do not puncture it in any way, and avoid exposing it to high greenhouse temperatures. Misuse of the mat can cause electrical shock or even a fire, so use caution with this product.