03 March 2015 By Sam Duke
March is one of the most exciting months on the gardening calendar. The sights of spring are hiding around every corner and you can really start to get going in the greenhouse.
The first thing to bear in mind is the unpredictable weather that March brings. Early spring can see wide temperature fluctuations which can be a problem – a bright sunny day at the end of the month can result in the greenhouse overheating; aim to keep the air temperature at around 7 – 18°C (45 – 65°F); this will involve heating the greenhouse at night and also ventilating and damping down the structure on cloudless days if required. Keeping the door and vents open more frequently as the month progresses helps to keep humidity levels down and prevent disease.
Seedlings need good light but young ones will still need protecting from the mid-day sun. If you do not have shades fitted to your greenhouse and find you need some – or additional ones – give us a call on 01730 826 900 and we will be happy to help.
Growing plants should be fed with a liquid fertiliser but take care not to overfeed them. A balanced formula should be used for leaf growth whilst a high potash feed should be used for flowering plants. Remember to keep actively growing plants damp, but not soaking wet. The Hydroleca on your greenhouse bench top helps to retain moisture.
Insects can start to become a problem this month – keep watch for greenfly, whitefly and red spider mite in particular. If evidence of bugs is found, spray with a greenhouse insecticide or investigate organic alternatives.
Pollinating insects are not yet present, so nectarine, peach and strawberry flowers must be pollinated by hand. Try to do this in the middle of the day and repeat for a few days to ensure success.
Carol from our marketing team adds "if you don’t have a greenhouse to get your seeds started, why not use a coldframe. We can supply freestanding coldframes, give our TLC department a call on 01730 826 900 to find out more."
In our video library, you can also find some useful tips from John Wood, Head Gardener at National Trust Hinton Ampner in Hampshire, about sowing seeds; we recommend you take a look as no doubt this will be your main focus in the greenhouse this month.
Have you got any tips for this time of year? Comment below, tweet us @Alitex.