Heat lovers will flourish, you may feel like lazing about, but at times, some plants need your help! It’s a fine art!
Keep an eye on weather reports.
Water is key.
- Water in advance when hot weather is predicted.
- Water early in the day as possible so your plants have as much moisture as possible during the hottest time. On the hottest days, a second watering may be needed.
- Don’t be confused by wilting. Some plants, like chard, shut down to conserve water when it is hot. They perk right back up by the next morning!
- Water deep and occasionally. Frequent light watering encourages lush growth but also promotes shallower roots so that the plant is less prepared to cope when there is a reduction or no water coming on a hot day.
- Remove water competitor weeds.
- Harvest frequently and thoroughly; make it easier for your plants to keep up with the business of staying alive. Ripening fruits demand huge loads of water and nutrients.
- Hydrozone – Plant water lovers, shallow rooted planties, together when compatible.
- Strawberry tip: On a raised mound, lay down an untreated pallet, or 3 to 4 inch wide boards side by side separated about 3 to 4 inches apart. Fill the pallet with soil, plant your berries. As the berry leaves grow, they cover the boards, keeping them cool, the boards in turn keep the soil below cool and moist and the boards feed the soil as they decompose.
Water if there has been a drying wind. Windy conditions can interfere with fruit set too, so if you can, create windbreaks. Use non heat radiating materials that allow some airflow so they won’t be blown over if you are in a wind pattern area. No air flow can make your garden a heat trap. In future, at planting times, anticipate winds, install trellises, planting them thinly to allow air flow. In SoCal ‘winters,’ they can block cold winds. In spring, put in some corn for filtered shade and as a windbreak. You may have to stake taller large bodied varieties of corn. Might choose varieties with less height that mature sooner, require less nutrients, and create less waste.
Keep your Mulch topped! Cover bare spots and replenish where your mulch is getting thin. 4 Inches is a good depth. Preferably use light colored mulches, like straw, that reflect the sunlight. If your mulch has meshed into a tight layer, use a watering spike so water gets to the roots of your plants. Straw, rather than a meshing mulch, is better for your veggies. But if you have Bagrada Bugs, REMOVE your mulch ASAP!
Container gardeners consider these terra cotta plant spike/bottle setups. Steady moisture right at the root zones! The adapter fits wine or plastic bottles! There are other variations. You can cut the bottom off a plastic bottle, for easy refilling! Cover with cloth and a rubber band to keep debris or insects from clogging your spike. One of the advantages of container gardening is plants can be moved into temporary shade if available if necessary.
Incorporate water holding compost into your soil, but also know that your soil only needs 5% humus, and over composting is not helpful.
WikiHow says: ‘In times of heat shock, a seaweed extract based liquid fertilizer treatment often reduces heat stress and it may help protect the plant in future.’ If your plant needs a feed, mix that kelp with some fish emulsion.
If you have tender plants, maybe seedlings, set up some temporary shade. Safely prop up some nursery plants flats with the fine mesh, or use some scrap lattice. For an easy custom fit, a simple set up is remesh, bent to the shape you want, anchored, covered with shade cloth. The beauty of shade cloth is it comes in ‘shade factors,’ the degree of blocked sunlight, and can range from 25% – 90% ! Salad greens do well with 50 – 60% shade factor. Heat lovers like squash and beans do well under 30% shade cloth. Or, simply pop in a well anchored umbrella. Power up some shade sails, an old sheet or dust cloths. Just be sure there is air flow – no baking your plants! When the heat is over, remove your covers promptly so your plants won’t get used to having them and suffer at the time of their removal.
If you live in a hot area, consider permanent options like this beautiful sliding wire canopy at Desert Botanical Garden! Install it East to West for all day shade when needed. This image is used by permission from Rock Rose Blog! Thanks, Jenny, it’s lovely! Please see her post for more clever and beautiful shade ideas ~ love your garden, be creative!
Design well ahead of time for ‘shelter’ plantings! In late summer/early fall, winter transplants, having shallow roots, will do well in partial shade of mature plants that will soon be pulled. This way, the sun will be available to the little ones when they are better established. In spring, plant corn or leeks, tall onions, north to south, that later allow filtered light to plants that need a little shade later on. Corn planted June/July can shade peppers or strawberries at the hottest August/September weather.
Too much heat, water stress
- Know that veggies have their own priorities. Some ‘bolt,’ go into flowering mode, at significant weather changes. They think the season has ended.
- Some plants like tomatoes, peppers, eggplant, stop flowering and fruiting when temps rise above 85 to 90 degrees F (depending on humidity) for an extended time. Humidity causes pollen to stick and not fall to pollinate. Dry heat causes the pollen to fall and not stick! At those extremes, no amount of sharply rapping your plant or its cage will help pollination.
- There are heat tolerant varieties, for example Heatmaster and Solar Fire tomatoes are two. Heirlooms are more fussy, hybrids less. Cherry tomatoes and the Oregon State U-bred parthenocarpic tomatoes, including Gold Nugget, Oregon Spring, Oregon Star, Siletz and Legend, are the exception, as they will set fruit over a wider temperature range than most large-fruited types. Parthenocarpic and cherry tomatoes will fruit throughout the heat of summer, even in Tucson, according to the University of Arizona.
- At 95 degrees, beans and peas simply drop their flowers. The exception is Rattlesnake beans that happily flower and fruit up to 100 degrees! At 100 degrees, corn tassels are killed, no pollination can happen and its all over for them.
When it cools down, your other plants will get back into production. Wait for it.
Here in SoCal we are facing more heat, less rainfall. Being mindful of how and when you use our water is important. Selecting heat tolerant varieties makes good sense. With long-term climate changes, we gardeners will become more skilled at hot weather gardening!