By Clodagh and Dick Handscombe
Practical gardeners and authors living in Spain for 25 years.
We are now in mid July, normally the beginning of the hottest four weeks of the year. Everyone will experience over 30 oC in the shade, some over 40. Resident readers will find it hot and even more so visitors from the UK. But that’s nothing to what many of your precious plants will need to endure if they are in sunny versus dappled shaded positions. The temperatures above are in the shade temperatures. In the sun temperatures can be considerably higher – put the thermometer you have in a shady porch or covered terrace in the midday sun for an hour and it will immediately go sky high and could in fact break a delicate glass thermometer.
So do take action now to minimize summer losses.
1. If you have not adjusted your irrigation system for summer conditions immediately double the amount of water per day for the next two months. If you find that some plants are still drooping water less frequently but for longer to ensure moisture is getting down to the roots. To pay for the extra water check that you are not watering unnecessarily long established shrubs and trees which by now will have deep tap roots. Fairly frequently we find that long planted fig and olive trees are still being watered daily and likewise oleander and gandula hedges.
2. Except for truly draught resistant plants such as cacti and succulents move potted plants into places where they will be in dappled or semi shade for much of the day.
3. On apartment terraces and balconies use awnings and blinds to shade plants during the hottest hours of the day. Most importantly recognize that plant containers can become very hot and therefore the growing medium in the containers will heat up increasing moisture losses by evaporation from the surface. With poor compost mixes containers can dry out in 24 hours or less. As illustrated in the table on page 119 of our book ‘Apartment Gardening Mediterranean Style’ typical watering requirements for drought resistant and thirsty plants under summer and winter conditions in containers may require six times the watering in mid summer to during the cool winter months even in semi shaded situations.
4. Both in the garden and in terrace pots mixing a little Terra-Cottem gel into the soil and composts at the bottom of planting holes has saved many a plant that was not watered for a few days during the holiday season. It can be purchased via www.terraverde.com. You can still use terracottem for established plants by digging a whole down the side of containers and pouring a half tea spoon of Terra-Cottem into the bottom of the hole or digging a hole or a trench around plants in the garden and doing likewise but naturally increasing the amount of Terra-Cottem according to the size of the plant. The above website gives good indications of how much to use.
5. If you planted new flowering or fruiting trees last autumn or in the spring digging holes around plants or trees to slide in empty water bottles or lengths of 5 cm diameter water pipe down to the root ball level enable you to give extra watering down to the developing roots. Many trees die each summer as they are only watered on a drip irrigation system to the same extent as smaller more shallow rooted plants. Don’t assume that damp surface soil means that roots six twelve or twenty four centimeters below the soil are damp and not drying out. If in doubt dig a hole alongside a number of shrubs and trees to check how deep the soil becomes dry.
So take care this year that plants as well as the family don’t get too sunburnt!
Clodagh and Dick Handscombe’s books include instructions for caring for plants during each month of the year. The books can be purchased from bookshops and via internet mail order sites such as Santana Books. At present they have a special summer offer for ‘Apartment Gardening Mediterranean Style’. It will save your garden as well as being a great present.
© Clodagh and Dick Handscombe www.gardeninginspain.com July 2011.