Growing Beds and Bags for Your Greenhouse

Even with a very large DIY Greenhouse, you will soon find that there is never enough space for everything you would like to grow. Fresh, bright red tomatoes, smelling of vine, juicy strawberries, bell peppers, red and green, herbs, fresh lettuce when nobody has them. And why not melons or potatoes? Not to mention all the beautiful flowers, for your home, or to replant in your garden. So many choices, so little space.

With your greenhouse benches and shelves, you are well under way to having a well-organized space to fit everything you need. But, you cannot put everything you want to grow in pots, it would simply not fit. Your seedlings will also soon overgrow your seed trays, and you will need to give them more space. Growing beds are one of the most important parts to a well-organized greenhouse.

Growing Beds on the Ground Level of Your Greenhouse

If you left a part of your greenhouse floor bare, you can plant many seeds and seedlings straight into the soil. You will need to add some organic matter and fertilizer to prepare the soil for healthy plants before doing so. But, growing on the soil level is not very comfortable in a greenhouse, and the plants are hard to reach in the limited space. You will also have to replace the soil frequently, as the fast growing plants will replete it of nutrients very quickly. Another problem is keeping the plants a steady temperature. The ground tends to get too cold in the winter as the cold seeps in from below.

Raised Growing Beds

For many the ideal growing beds for greenhouses are raised beds. The best time to build your raised growing beds is before you bring the benches and shelves into your space and can still configure your layout.

There are ready-made raised growing beds you can purchase online or in your local garden center that are made of a heavy-duty rigid plastic. They are easy to assemble and come in different sizes, so you can choose to place them along one or more greenhouse walls. You should line the raised growing beds with a special plastic liner, which will prevent soil from coming out, but will still allow excess water to seep out. You do not want your plants to get waterlogged.

Another type of ready-made raised growing beds is made of hardwood lumber (cedar, locust or redwood.) Be careful with treated pine, as the chemicals used for the lumber treatment are toxic and will seep into the soil, and through the soil may be absorbed by plants. Wooden raised growing beds are assembled similarly to the plastic ones, with the liner to keep things tidy.

DIY Raised Growing Beds

Of course, as true DIY-er, you might prefer to make your growing beds yourself. You can use anything from left-over lumber, to cinder blocks, regular bricks, pieces of rocks, old barrels cut in half, even old tires and washing machine drums. Anything that will allow you to raise the growing bed off the ground and create a frame for the soil will do. Again, do not use treated lumber, chemicals are dangerous for plants and make sure that there is ample drainage.

Soil Mix

It is a good idea to put a layer of few inches of gravel at the bottom of your growing bed, just as you would in raised bed in your garden, to provide good drainage.

The soil sold for greenhouses is peat-based compost, usually sold in nurseries in large bags. Of course, you can make your own mix in your garden, using your own compost and your own organic fertilizer generously provided by your cows, horses or chicken. Make it heavy on peat moss as peat holds water and nutrients well. Bags of premixed soil also have nutrients mixed in, so if you are making your own mix, you will have to add some, whether organic or chemical.

Seeds for Greenhouse Growing Beds

Most people use any type of seeds they can find in the garden center, or they get as a gift from friends and neighbors. But, there are few differences between seeds of plants that will be grown outdoors and those grown in a greenhouse. Seeds for growing in a greenhouse have special characteristic useful for greenhouse growing:

1. They don’t have to be pollinated, they are self-fruiting;

2. They often use vertical space better, such as vining tomatoes;

3. They are more disease-resistant and vigorous varieties;

4. They are not as dependent on a day length, so they grow and flower better during short winter days.

This is particularly important for some types of tomatoes, cucumbers, zucchini, winter sweet peas and snapdragons. Look for bags of seeds that are specifically marked as ‘suitable for greenhouse growing.’

Greenhouse Grow Bags

Grow bags are an interesting option for growing plants in a greenhouse. They are not much more than bags made of the same type of plastic you used for your grow beds liner, filled with soil. You do not need a growing bed, you can place your grow bags directly on the greenhouse floor, or on a sturdy greenhouse bench. Slice the top of the bags leave a square space for planting seeds; simply put some seeds in, water and watch your plants grow. Some grow bags may even come with an assortment of seeds.

The soil in grow bags is peat-based compost, it contains essential nutrients and trace elements and a special wetting agent for easier watering. Contained growing in a bag also reduces the danger of plant being damaged by pests and diseases.

You can make your own grow bags, or simply use bags of pre-mixed soil you bought at the garden center. Just be sure that you poke some holes at the sides for easy water drainage.

What Can You Grow in Your Greenhouse Grow Beds?

Traditionally, besides flowers and exotic plants, people have been successfully growing in their greenhouses a wide range of edible plants: herbs, tomatoes, peppers, cucumbers, lettuce, melons, strawberries, eggplants, zucchini, French beans and many others. Some adventurous greenhouse owners are experimenting with potatoes, corn and watermelons, with great success.

Once you harvest the first crop of your own greenhouse fruits, flowers or vegetables, you will be ready to experiment with things your family or friends might like. Ask your family what they would like to grow and try to involve your kids if you have them.

Your DIY Greenhouse will provide you with days and hours of hard work, great pleasure in seeing the fruits of your labor, and a full fridge of fresh produce.

Leave a Reply