The base fertilizer contained in all composts will be used up by the plants within about eight weeks. This is because there is less soil life than outside to create and release nutrients, and because constant watering tends to
wash away any nutrients that are present more quickly. Mini- Greenhouse plants must therefore be provided with additional food. Use either the home-made animal-manure tea or a proprietary liquid seaweed or animal-manure feed . I find seaweed ideal for most purposes because it contains the full range of nutrients needed for healthy plant growth. Intervals between feeds will vary according to the crop. Always be sure to use fertilizers at the recommended strength and frequency; overfeeding can do more damage to plants than underfeeding. Generally, plants that are expected to grow and produce fruit at the same time - like tomatoes and cucumbers are more demanding than most plants.
Automatic watering systems
An automatic watering system will save you a lot of time. There are many types available but from experience, the simplest is just as efficient as the most expensive. For plants in planters, put a sheet of plastic over the shelves and cover it with a length of absorbent material known as a "capillary mat". If the mat is kept moist, the plants can take up water whenever they need it.
mini- greenhouse plants
Plants that are grown inside rely on you for food and water, so you must be committed to giving them constant attention. In the summer the plants will need a lot of water. In the early spring, however, the water from the tap is likely to be much too cold for tender
young seedlings. To avoid damaging the plants, fill the watering can after watering and leave it so that the water has warmed up by watering time the next day.
Delicate young plants and seedlings must be sprayed with water using a fine nozzle to prevent damaging them. Use a watering can with a fine rose and with a spout long enough to reach to the back of the shelves.
Always water in the morning rather than late in the day. Watering "little and often" is not a good idea; most mini-greenhouse plants do better when they are given a thorough soaking and then left for a while before the next watering.