Make the most of your greenhouse this autumn

Tomatoes anyone?
Tomatoes anyone?

By late September the greenhouse is beginning to lose its sparkle.

Most of the food plants that looked so vigorous and productive at the height of summer are showing signs of decline, ornamental types are also starting to look ragged.

Tomtato crop!

Tomtato crop!

We can no longer splash water around to sustain growth and control temperature as if it were the height of summer. It’s time for a changeover and different mind-set.

Tomatoes are present in our cold greenhouse from late April to deepest September, so there’s a feeling of loss when they finally go. The process begins with sowing of seed once I’m convinced that enough warmth is being generated by the sun to sustain young growth. Even then, fleece is standing by for those nights the temperature dips. May and June see steady growth and transfer to slightly bigger pots as the roots develop. By the end of June they are in their final pots with cane supports, and standing on the long greenhouse border.

This is a reliable system because it encourages two sets of roots; first in the pot and then in the border. I view it as a belt and braces job just in case a root disease appears. Once the first truss has set a fortnightly liquid feeding regime begins. Food is applied via the pot and the border is watered regularly to encourage root penetration.

The daily plant health checks and constant removing of side shoots is rather therapeutic, and a sense of affinity with the plant develops. The later removal of lower leaves to increase air circulation and discourage disease is as much for the plant`s benefit as that of the gardener protecting his crop. So it seems fitting that recycling brings the whole process to a positive conclusion.

The top growth is chopped-up and composted, whilst the growing medium is added to ornamental borders as a soil conditioner.

Nor is the substantial remainder of the crop forgotten. There are lots of green tomatoes in the collection and they can be turned into chutney, but even the smallest of these will ripen given the chance. Spread newspaper on the greenhouse staging, or on the bed in a spare room, and lay them out in the light. Place an unpeeled banana amongst them that will speed-up the process.

Tomtato plants I grew on trial in pots this year for their novelty value, produced long trusses of sweet cherry tomatoes which I’d certainly grow again. However, the potato crop that developed at the roots was disappointing. The haul from one was a large single potato (one serving of chips). The other pot delivered two potatoes, and the third will be unearthed at our garden club on Tuesday evening. Don’t hold your breath!

Grafting tomatoes onto potatoes is possible because they both belong to the family solanaceae. The practice has been around since Adam was a lad but never took-off commercially. To get a decent potato haul from a single grafted specimen you need to plant into a border under glass which has a good organic content, and offer back-up with food and water.

We have not pulled up all of the traditional tomato plants yet, just three remain. These are the Italian plum-shaped variety San Marzano, grown this year for the first time. They were late in developing and are just beginning to ripen. All I require is one good fruit so that seed can be saved for next year.

The process is simplicity itself.Lay a double kitchen towel on a bench in preparation then gently pull the selected fruit apart, teasing out the seeds with a spatula. Spread them over the tissue and allow to dry in the daylight over a few days. Collect the seed and seal it in a paper envelope that can be stored in a cool, dry place until next spring.