Tasks for your greenhouse this January

Growing inside a lean-to greenhouse

After the chaos of the festive period, you will be pleased to hear that the gardening calendar starts off with a much calmer vibe. January provides the opportunity to snuggle down in your favourite armchair and finally read through those seed catalogues; we recommend browsing through a few gardening books for extra inspiration.

The new year is a great excuse to seek new varieties to experiment with, it is important to remember that the plants you decide to grow must be able to happily co-exist side by side; a multitude of plants all requiring widely different temperatures, light and humidity levels are unlikely to thrive. Unless your greenhouse has been designed to have separate partitioned zones in which different growing environments can be maintained, we recommend double checking the companion planting tips for each plant you choose.

This quiet period provides the perfect opportunity to make sure your greenhouse is in perfect working order and functioning as it should be, ready for the season ahead. Our ‘Clean & Care’ service is the ideal way to ensure your greenhouse is in tip-top condition and looking her best for the spring. Please contact us on 01730 826900 for further information.

Frost-sensitive plants do not need a lot of heat in the winter months, a good rule of thumb is to aim for a minimum temperature of 5 – 7°C (42 – 45°F), certainly no higher than 12 - 15°C (55 – 60°F). During the night you may find it necessary to cover these particular plants with a horticultural fleece, straw or even newspaper if night frosts are forecast.  Installing a min-max thermometer will help you keep track of temperature and ensure that any heaters are working as they should.

Many of us go in to the new year with a resolution for better health and well-being and it’s no different for our plants; we also want to protect them from disease inside  the greenhouse. Keep the atmosphere dry and use water sparingly unless plants are in flower, it is good practice to water early in the day and keep it directed to the roots where it is needed. Be careful not to splash the floor, benching or foliage with excess water as this will only increase humidity inside the greenhouse and increase the risk of pests and mould. If you already notice some grey mould or whitefly don’t panic, now is the best time to combat them with a spray. Be sure to keep a close eye on all of your plants and remove any dead flowers, as well as yellowing or diseased leaves to keep them fresh.

Despite the colder weather your greenhouse will still need to be ventilated, however you will need to keep in mind that on damp, foggy days the side vents should be closed; use them only on the dry and sunny days. The best time to open them is in the morning and close them again mid-afternoon, this will conserve the heat of the sun before night falls.

If you have early sowings of sweet peas or onions, now is a great time to pinch them out and plant in to larger pots. January is also a great month to take cuttings of tender plants. Make sure any compost used for sowing or potting is brought into the greenhouse to warm up several days before it is used to prevent seeds and young plants being chilled.

What advice do you have for greenhouse owners this January? We would love to hear from you. Share your tips on our Twitter @alitex or email me, sam.duke@alitex.co.uk.

Tags: greenhouse, growing, Winter, January, Temperatures