Use starting mix to avoid future problems

During the last few weeks I have talked about starting seeds. Today I would like to answer a few questions that have come in on this topic.

Why do I need to use seed starting mix when starting seeds?

Seed starting mix contains peat moss, perlite, vermiculite and a small amount of lime. They’re heated to a high temperature to kill off any bacteria. When starting seeds you need to ensure they receive enough moisture and light. Seed starting mix provides the perfect amount of soil drainage because it holds enough moisture to allow the seeds to germinate. It is also a finer soil which is important when you’re trying to encourage good root growth from the seedlings. Spending a little bit more on the right soil early on will prevent a ton of problems later.

When do you transplant seedlings?

I start my seeds in small shallow trays about five to 7.5 centimetres deep — but once the seeds have germinated you will need to move them into a larger container or pot. The general rule of thumb is that when a seedling has two to three “true” leaves it’s time to transplant it.

When you plant a seed, the cotyledons are the first leaves to emerge. These leaves will look different from leaves that grow later. The purpose of these leaves is to provide stored food to the seedling for a short period of time. True leaves are what grow next after the cotyledons. The true leaves start generating energy through photosynthesis that will help feed the plant for the rest of its life.

Just remember, it isn’t how tall but how many true leaves your plant has that will determine when you should be planting seedlings out. I like to transplant my seeds into recycled yogurt containers or pudding cups — don’t forget to put a drainage hole in before you plant and use a good quality potting soil.

Why do my seedlings grow real tall and often fall over?

Light is a real challenge when you are starting seedlings. Because of the shortened daylight hours many gardeners grow seeds and other plants under grow lights to lengthen the day. When you are growing seeds you need to provide as much light as possible. They need about eight hours of consistent light every day. If you’re using grow lights they should be no more than 15 centimetres above the seedlings to provide the right amount of light. So as the plants grow you will need to change the distance they are from the light. One method is to start the seeds on a stack of books or something that will put the tray closer to the light. As the plant grows, you remove books and drop the tray down as your plants grow toward the light, always keeping the distance between the two at 15 centimetres.

Before you know it we will be planting theses seedlings out in the garden.