Glasshouse garden tips

Garden tips for your glasshouse care

The Alitex Glasshouse in the Walled Garden at Cowdray, Midhurst from afar, 

a photo by Alitex UK on Flickr.

HAVING worked in glass-houses of all shapes and sizes, I've come to realize that each has its own character, and the plants inside can be as various as alpines, figs, tomatoes or cymbidiums. But greenhouses also have many things in common, not least when it comes to 'house-keeping', and essential main-tenance is best done before the new season begins in earnest.

First, a bout of ruthlessness. Every glasshouse I have ever worked in has contained some no-hopers. These are the plants that are carried forward from one year to the next. toil, watered, kept warm in winter, ventilated in summer, but which never look good enough to plant out or put on display. They take up bench space long after their useful life is over or the original reason for growing them has been forgotten; we care for them out of habit and they are both time and space wasters. Cut your losses and get rid of them now. Space will soon be at a premium.

Next, some valeting. All remaining plants should be corralled at one end of the greenhouse, and lightly covered with polythene to protect them. Then, the house (and the gardener) can be washed from top to bottom with warm water and disinfectant. This serves two purposes—any pests or diseases that have been comfortably overwintering will be washed out. and the removal of dirt and algae from the glass (both inside and out) will increase light levels within the house significantly.

As cleaning progresses, in situ plants can be moved along the benches out of the way, broken panes can be repaired, rotten wood treated or replaced, and equipment such as mist benches, propagators and automatic vents tested to make sure they're in good working order.

Glasshouse pots

Previously used pots and trays should also be scrubbed clean in the glasshouse, as fungal diseases in particular like to lurk in the old compost that clings to used pots. Stacking clean pots in order of size and shape may seem a bit obsessive, but, later on, when a batch of two dozen seedlings is ready for potting up, it will make complete sense.

It does no harm, at this stage, to think objectively about ergonomics. Is the potting bench close by, or do plants have to be carried outside of the glasshouse in the cold in order to reach the potting shed? What happens to spent compost and used pots and trays? Can the dirty compost bins be emptied easily, and are the hosepipes long enough to reach all parts of the glasshouse? Now is the time to annul to I licse details and make improvements.

Ordering glasshouse supplies

The final task of our garden tips for glasshouse involves some much-needed retail therapy. Ordering glasshouse garden supplies now will significantly increase efficiency later in the season; some or all of the following will be needed: seed trays, pots, fresh compost, grit, watering cans, roses and hoses, heating oil, labels, pens, liquid food and slow-release fertilizer. Pest and disease control can be tackled as and when

it occurs (no point in stocking chemicals you might not need), but, even at this early stage, a watchful eye must be kept for pests such as greenfly, red spider, mealy bug, whitefly and vine weevil, together with
diseases such as damping off and mildew. At the very least, we should be able to recognize these and to know sufficient of their control to be able to quickly send for the appropriate remedy.

A hand lens is a valuable tool; I once wasted several days treating a hatch of flagging seedlings with fungicide against damping off, when, in fact, their stems were being eaten by the larvae of springtails. The symptoms were identical, but insecticide, not fungicide, was needed. Stopping an outbreak before it gets out of

hand is the key to success here, and some greenhouses have very effective 'quarantine' areas, partitioned off from the rest of the glasshouse, where plants can he nursed hack to health without danger of infecting others nearby.

There is a great deal of satisfaction to be had once all the preparations for spring are completed. To survey a sparkling glasshouse, equipment in tiptop order, supplies ready and waiting, is almost as exciting as picking
up that first seed packet and starting to sow with our great glasshouse garden tips.