Cold greenhouse or heated greenhouse?
Obviously, both do not have quite the same functions:
- Cold greenhouse: it is the most common and essentially helps protect plants from cold, wind and humidity in winter. Before the arrival of spring, it allows sowing to be made earlier and accelerates the process of seed emergence to the extent that it stores heat as soon as the sun comes out.
- Heated greenhouse: it is a greenhouse equipped with heating which allows it to maintain a moderate temperature throughout the bad season. It is possible to grow vegetables there all year round.
Likewise, the work to be carried out in the greenhouse is not the same, because the heated greenhouse is generally maintained throughout the year.
Regarding greenhouse maintenance work in March
In the case of a cold greenhouse, March is the period when it really comes back into service. It is therefore necessary to maintain it well to ensure a healthy place what you are going to sow and plant. This requires several tasks to be carried out.
To clean
If you didn’t have the time or inclination to clean your greenhouse in February, the beginning of March is the last end to do it. In fact, it will then be too late, because the space will be occupied by young plants and seedlings, which will make cleaning complicated. To clean all the elements of your greenhouse, you can use a mixture of water and vinegar which will allow you to disinfect everything at the same time.
Ventilate
Ventilation of the greenhouse must be as frequent as possible. Therefore, as soon as the weather permits, it is important to ventilate this space to prevent the development of fungi and mold.
Start protecting from the sun
If you live in a region in the south of France and your greenhouse is in a location exposed to the sun, start protecting the seedlings from direct sunlight either by fixing curtains or applying Spanish white on the windows.
Water
As the temperatures are milder, it is necessary to start watering more frequently to prevent the plants from suffering:
- For plants that you have overwintered in your greenhouse, such as pelargoniums, fuchsias, oleanders, bougainvilleas, etc., resume watering once a weekespecially if the sun is shining.
- If you did some sowing in February, remember to water the young plants well to accelerate their growth. This is especially true if you have seeded in peat pots, as these tend to dry out very quickly.
To watch
Continue to monitor overwintered plants and young plants closely to ensure that no pests have entered or disease has started. The sooner you spot them, the easier it will be to get rid of them. Pay particular attention to aphids to avoid their reproduction.
As for seedlings to be done in a greenhouse in March
The greenhouse will allow you to carry out different sowings during the month of March. However, it is important to distinguish between what you can sow in a heated greenhouse and what you can sow in a cold greenhouse.
In a heated greenhouse
Some plants are more sensitive to cold weather, so they can only be sown at this time of year in a heated greenhouse or on a warm layer in a cold greenhouse if you have prepared one.
This is the case for summer vegetables such as eggplants, peppers, chili peppers and tomatoes. These crops need more time, so it is best not to sow them too late, but they also need heat to be able to germinate. At the end of March, you can start sowing melons. Beyond these specific vegetables, you can, of course, sow anything that can be sown in a cold greenhouse in March.
In a cold greenhouse
In a greenhouse that is not equipped with a heating system, you will also be able to carry out different sowings:
- If you are growing your onions from seeds, now is the time to start your seedlings.
- You can also sow leeks, as well as aromatic plants such as parsley, chives and coriander.
- Spinach and celery will also find a place in your greenhouse from March.
- Consider sowing salads on a regular basis to benefit from staggered harvests.
- As for flowers, you can also sow your summer flowering plants. You will benefit from flowers earlier in the season. You can sow zinnias, hibiscus, ipomoea, cleomes, passion flowers, black-eyed Susan, etc.
- You can also get your summer bulbs started such as dahlias, cannas and begonias by placing them in terrines filled with peat and sand. It won’t take long for the first leaves to appear.
About overwintered plants in your greenhouse
You may have put some of your plants in your greenhouse to protect them from the cold and bad weather throughout the winter. It’s also time to take care of them to prepare them for their return to the open air:
- If your region has a sufficiently mild climate and depending on the plants, you can start taking them out. This may be premature in some areas, but weather permitting, you can at least take them out during the day and then bring them in at night.
- Maintain these plants by removing the leaves that have dried and pruning them. If you have hibiscus, you can prune them by a third. Likewise, if you have not already done so, prune the climbers that you have overwintered in your greenhouse, as well as the pelargoniums to encourage the growth of new stems.
- You can take cuttings from dahlias, lantanas, anthemis, tuberous begonias, etc.