The Gardening Year for the Indoor Garden


Clear away any plant debris and scrub the inside of the greenhouse with garden disinfectant. Watch out that greenhouses do not overheat on warm days; open them up to cool them down and to allow air to circulate. Keep an eye open for pests and diseases and deal with them as they occur.

Prepare greenhouse beds and soil benches and start sowing bedding plants, if not done in late winter. Take leaf and softwood cuttings for propagation in early spring. Pot on, re-pot, or renew the top-dressing of established plants as necessary.

Once growth is under way, start feeding and increase watering; mist-spray plants that need high humidity. Remove any dead leaves and flowers unless seed is needed. Thin out and harden off seedlings, reading for planting out in the open ground. As the level of sunshine increases, apply shading to the glass and ensure that there is adequate ventilation.


Ensure that the greenhouse or conservatory has adequate shading and ventilation. A good circulation of air will help to prevent many pests and diseases; keep a close eye on plants and treat any that show signs of infection or infestation. Damp down the floors to maintain humidity and to reduce populations of red spider mites.

Feed and water plants regularly, and remove dead leaves and flowers where necessary.


Autumn is the best time to undertake a major clean of the interior of the greenhouse, as the weather is still mild enough to allow tender plants to be left outside whilst the work is being carried out. Scrub down surfaces well, and fumigate with insecticidal or fungicidal smoke if required. Remove shading when the sun has become less intense.

Bring in tender plants or winter-flowering plants from outside and repot or top-dress; make sure containers are clean before bringing them inside. Reduce the amount of watering and feeding of other plants as their growth slows.

Avoid cold drafts through the greenhouse, insulate where necessary.


In the winter, keep the greenhouse clean by removing any debris. Make sure pots and seed trays are ready for spring use by soaking them in diluted garden disinfectant, rinsing them thoroughly with clean water.

Reduce the frequency of watering and avoid a damp atmosphere by using ventilation or a de-humidifier. Plants in unheated greenhouses should be kept almost dry to their prevent roots from freezing; insulate by plunging pots into sand or by using plastic sheeting or similar material.

Keep an eye out for aphids and nip off dead or yellowed foliage.

Prepare potting compost for seed trays so that cuttings and seeds may be planted when required. Bedding plants may be sown in late winter.