With the arrival of warm temperatures, cool weather plants have really taken a beating and are fading fast. Pansies, mimulus, dianthus and stocks are starting to go downhill rather quickly, but fortunately there’s still time to plant heat-loving and drought-tolerant colour to keep our gardens looking good until fall.
When planting at this time of year, there are a few things to bear in mind. During warm spells, do your planting in the evening so your plants have at least overnight to acclimatize. It really helps for the first day or so to lay a bit of Remay cloth over new plantings to filter the worst of the sun’s intensity and to allow those roots to take hold. It’s also a good idea to prepare your soil with a generous amount of damp quality compost, well-rotted manures and starting fertilizer to speed up the rooting process. Because you have no time to lose, be very particular about the plants you purchase at this time of year. Plants that have been crowded for too long and look tall, hard and lanky will not perform well for you. Choose either fresh new plants or ones that have been repotted into larger four or six inch pots.
It’s wise to choose plants that not only love the heat, but once established, will also tolerate some drought. On top of my list are gazanias. These beautiful, huge daisy-like flowers are just a blaze of vibrant orange, yellow and bronze shades all summer long. They add a unique flavour to any garden, and for the very best effect, they should be used in groups or mass plantings.
Portulacas (or the ‘moss rose’ as they are sometimes called) are right behind them for a great show in dry conditions. They are simply breathtaking with masses of vibrant bright double blooms that just don’t quit. They thrive in sunny, dry, hot spots; they do poorly in rich heavy soils. Portulacas should also be used in mass plantings, and they will often seed themselves for another great display next year.
For shady areas, New Guinea impatiens, browallia, tuberous begonias and coleus perform like magic with a minimum of water, once they are established. Be sure to check out the new sun-tolerant coleus varieties. At the outdoor trials in Chicago last year, the temperature was 96°F, and these coleus were just soaking it up!
Wonderful old-fashioned cosmos is another great drought-tolerant plant. The new dwarf ‘Sonata’ series is truly spectacular.
No garden would be complete without salvia, and you can’t plant salvia without its very best companion, Dusty Miller. Experiment with both ‘Salsa’ salvia and my favourite ‘Victoria Blue’, or try their new cousins, the more compact ‘Rhea’ or the blue and silver variety called ‘Strata’.
Did you know that fibrous begonias, geraniums, ivy geraniums, annual rudbeckias, canna lilies, vinca, cleome, zinnias, ‘Triploid’ marigolds and petunias are drought tolerant too? There is still plenty of time to add spots of colour to perk up your garden, and it’s nice to know there are plants that love the summer heat.