I always have a bit of a conundrum at this time of year in the greenhouse. The plants are really growing away strongly now and tomatoes and aubergines are forming (no melons yet though…). But holidays hove into view. Holidays and greenhouses really don’t mix particularly well. At this time of year greenhouse plants want watering well every day and a whole spring and summer’s worth of work can be lost for a week’s holiday. But there are some things that you can do to help your plants survive a bit of neglect and hopefully head into late summer looking good and producing plenty.
First off though, it can’t really be done without either a very helpful neighbour who is prepared to pop in and water once a day, or a watering system. Watering systems can be set up so a long hose runs around all of your pots with nozzles that drip water into each. You can then attach a timer to the tap end and allow the water to drip into the pots for an hour or so a day. They are a lot of fuss to set up but a brilliant solution. If you are having a neighbour call in, make it easier for them by setting up a hosepipe, or by ensuring water butts are full, but also by using every possible way of cutting down on the need to water.
The first thing requires a bit of time travel. You need to set up your containers right at the beginning of spring to be ready for this time. Use a good peat-free compost that holds plenty of water, such as Carbon Gold compost, or Dalefoot Compost, which is made from composted sheep’s wool and bracken, and both of which stay moister than most composts, for me. I go a step further and mix in water retaining granules before I fill my pots – they expand into a jelly like substance when they meet water and then release it slowly to the compost and plant roots surrounding them. If you didn’t do this this year then make a note to do it next year. Even if you aren’t going on holidays at crucial weeks of the year it will make your job easier and your plants happier.
Secondly make sure you use the biggest sized pots you can – the larger the reservoir of soil the slower the pot will dry out. If you can plant direct into soil then all the better, as at times of water stress their roots will be able to stretch out deep into the soil and reach depths that just don’t exist in a pot. Shading is really important because it will cut down on heat in the greenhouse and that will reduce the amount of water they lose from their leaves, which in turn will need replacing in the pot. In a similar vein if you can cluster plants together they will crate a bit of a microclimate, shading each other and creating a moister atmosphere around the leaves, which again means less watering is needed. Make sure that every pot has a saucer underneath it to create a reservoir of water for the plants to draw on. I have bought several big black deep lipped trays to place under my tomato plants, which are the thirstiest of the lot. I – or my helpful neighbour – can fill them to the brim and then have to water less often. Keep windows and doors open day and night and ask your neighbour to water the floor to cool the whole greenhouse down on hot days. With luck you will return from your holiday relaxed and rested and with a good crop of tomatoes on its way.