How to keep your plants alive when you’re on holiday
Take action to stop indoor plants drying out, outdoor pots suffering and slugs arriving
Colourful kale leaves growing in an Irish garden. Photograph: Richard Johnston
Group your outdoor pots on a table
If you are or have ever been the parent or guardian of young children, you’ll be familiar with the occasionally weighty feeling that comes with being responsible for young life. Heaven forbid you might neglect to keep your young charges watered, well fed, happy and protected from danger. I say this because something very similar is true of all dedicated gardeners. Like anxious parents, that all-important question of how our plants will survive while we’re off on our summer holidays is enough to give us heart palpitations. What if there’s a heatwave? A drought? Or an influx of slugs?
The good news is there’s plenty that can be done to keep your plants content while you’re away. Let’s start with any container-grown specimens, whose root systems are especially vulnerable to drying out and sudden extremes of temperature.
In the case of indoor or house plants, the simplest method is to collect any pots or plants light enough to be easily lifted and place them together in a sink or bath lined with a couple of thick, wet towels. Give them a really good watering just before you leave and make sure to pull the curtains or blinds in the room to protect them from direct sunlight. With indoor plants in pots that are too big to move, the upside is that they’re also less likely to dry out. So follow the steps above – generous watering, blinds down, heat off – and if you can fit a shallow saucer under the base, fill it with water before you leave.
If you grow a lot of your garden plants outdoors in pots and containers, then you’ll need to do something similar. Move these somewhere cool but sheltered, out of direct sunlight and away from warm, drying winds. Grouping them tightly together will also help slow the process of transpiration (the process by which water moves through a plant). A mulch of fine horticultural grit or fine bark chippings around the base of the plants will also help keep the compost moist as will placing shallow saucers or trays of water under each pot.
Garden slugs and snails can’t swim
Unfortunately these kinds of cool, damp conditions are perfect for slugs and snails, so it’s also worthwhile sprinkling a few organically-approved slug pellets around the base of the plants before you leave. As an extra precaution, you could place the pots (on their saucers) on a garden table, with each of the legs of the table in a bucket of water (garden slugs and snails can’t swim). But make sure to carefully check the bases of the pots for any lurking gastropods or molluscs (snip/crush underfoot any you find), and add a sprinkle of pellets in case there are slug eggs hidden in the compost that might hatch out in your absence.
With plants growing in greenhouses or polytunnels where temperatures are far higher and the effect of the sun’s rays intensified, there’s a much greater risk of these dying from lack of water or extremes of temperature if left untended for more than a couple of days. In this case, you can help to reduce temperatures by giving the ground a really good soaking then covering it with a layer of organic mulch (damp grass clippings from a regularly mowed lawn, for example), leaving doors and vents wide open, and temporarily providing some sort of shade in the shape of garden fleece or shade netting suspended above the plants.
With greenhouses, there are also various types of shading paint that can be used to coat the surface of glass (available from good garden centres). Opaque in bright sunshine but translucent in rainy weather, these help regulate temperatures and protect plants from the damaging effects of prolonged exposure to intense sunlight.
Another useful way to help your glasshouse or polytunnel-grown plants survive in your absence is to fill recycled plastic milk cartons or water bottles with water, then use the heated tip of a needle to make a very small piercing in the base before half-burying them (pierced end in the ground) next to plants to provide a slow drip-feed of water to the plants’ root systems. Also consider the use of self-watering plant trays (from good garden centres and from polydome.ie); these have capillary matting that allows container-grown plants’ roots to wick up water from an in-built water reservoir, dramatically reducing the need for regular watering.
Unfortunately, even with all these careful precautions, very thirsty species such as tomatoes, courgettes, cucumbers, French beans and dahlias won’t survive more than three-four days in a hot glasshouse or polytunnel without additional water. In this case, consider asking a reliable neighbour or friend to pop in occasionally and water as required, with the offer to reciprocate in kind when they’re away.
A pricier but efficient alternative is to install an irrigation system set to a timer. Cork-based Fruithill Farm supplies battery-powered timers that can be fitted to a drip irrigation system installed in your glasshouse or polytunnel, and are happy to give advice on setting up a watering system to suit particular requirements (fruihillfarm.com). Water-efficient automatic irrigation systems with rain sensors (so that they turn off when it’s raining) can also be installed outdoors. Dublin-based firm Irritec (irritec.ie) offers a range of options (from €800), some of which are smart wifi-controlled systems that can be monitored and adjusted from anywhere in the world using an app (hunterhydrawise). This way, whether you’re sipping a glass of chianti in sunny Italy or whale-watching in Quebec, you can rest assured your garden is thriving in your absence.
This week in the garden
At this time of year, cabbage white butterflies love nothing more than a neat line of thriving brassica plants – examples include cabbage, broccoli and kale) to use as host plants by laying their tiny eggs on the underside of their leaves.Once the eggs (laid in clusters, these can be yellow or pale cream) hatch out, the young larvae/ caterpillars do a lot of damage by quickly devouring the plant. Pigeons also love to eat the foliage of brassicas, which is why it’s so important to protect young plants. Do this by using a temporary cage of either green netting or Bionet draped over flexible hoops of plumbing piping or bamboos.
If you’re keen to garden organically but need some practical advice, then a guide to the principles of organic gardening is available to download for free from Garden Organic (gardenorganic.org.uk), the long-established British organisation formerly known as the Henry Doubleday Research Centre. This very useful guide conveniently divides its advice into separate categories, from “best organic practice” and “acceptable but not advisable” to “not acceptable in organic practice”. So, for example, if you’ve been wondering about methods of weed control, then the best organic methods include the use of organic mulches, close spacing between plants, and ground cover plants, while the use of conventional weed-killers such as Round Up is not organically acceptable.
Dates for your diary
Saturday, June 24th- Sunday, June 25th (11am-5pm), Mount Stewart Specialist Plant Fair, Newtownards, Co Down, admission free, see nationalatrust.org.uk.
Saturday, June 24th (10am-4pm), Botanical Plaster-Casting Workshop, with Deirdre Crofts at Dalkey Garden School, using fresh plant material to create botanical plaster plaques, €80 includes lunch and materials, see dalkeygardenschool.com.