July puts a strain on any gardening enthusiast. Nurseries continue to offer colorful and inviting summer annual plants, but the heat waves and drought that increasingly affect many areas make the survival of even established plants complicated.
This gap between what the shops offer and what the climate allows is becoming a common problem. Climate change means that traditional sowing and transplanting calendars no longer correspond to actual garden conditions. An intervention that ten years ago would have been uneventful can today turn into a real risk if temperatures exceed 35°C.
The challenge of climate change
Experts agree: episodes of extreme heat and sultriness, amplified by phenomena such as El Niño, are today the most unpredictable variable for those who cultivate a garden. However, this does not mean having to completely give up planting in summer. The key is to understand which species tolerate the heat well, which are better to postpone until a cooler season, and how to help the new plants take root in the best way.
Because the heat makes everything more difficult
The main problem is not the heat itself, but the effect it has on the roots. When a plant is transplanted from the pot to the ground, it goes through a period of transplant stress: it must develop new roots while continuing to support the leaves and stem. Intense heat complicates this balance because it accelerates the evaporation of moisture from both the soil and foliage.
Even native species need time to develop a solid root system in milder seasons, before they can cope with prolonged periods of heat and drought. Planting in midsummer means asking the plant to survive the harshest conditions of the year before it has even had a chance to establish itself.
This is not a new phenomenon, but the window of extreme heat is widening year after year. Many gardeners are reacting by anticipating sowing, in order to ensure that the plants have a root system already formed when the peak heat arrives. For the same reason, planting in the fall is becoming an increasingly popular option.
As a general rule, it is best to avoid planting when temperatures consistently exceed 29-30°C. With temperatures close to 32-35°C, many plants begin to divert energy towards pure survival instead of root development, because photosynthesis becomes less efficient. However, not all plants react in the same way: heat-loving flowers and vegetables do well, while cool climate crops struggle much more.
What to avoid planting in July
During a heat wave, some choices come with risks that aren’t worth taking: chances of survival in the first few weeks are low, time and money invested are at risk of going to waste, and even plants that resist are often left weak or permanently stunted.
Cool climate vegetables
Lettuce, arugula and similar crops are among the first to suffer when temperatures rise. They tend to flower prematurely, become bitter, or fail to take root at all, because their broad leaves lose water very quickly through evaporation.
Plants with broad, thin leaves
Hydrangeas are beautiful, but they’re not the most sensible choice for a midsummer transplant: The large, thin leaves waste a lot of moisture, adding stress to a plant that’s already trying to take root.
New lawns and turf
Laying turf of freshly cut grass is probably the project to put off the most. In the height of summer, a newly laid lawn can require multiple waterings a day and very high maintenance costs. Spring and autumn offer much better conditions for rooting.
What can still be successfully planted in July
The good news is that July is not a lost month for gardening: you can still intervene with the right choices.
Heat-loving annual flowers
Many species flower well in the heat and can provide months of color before autumn. Sage and lavender are two great choices, naturally adapted to sunny, arid conditions. Zinnias, cosmeas, vinca, angelonia and marigolds are also reliable options: plants designed for summer, which often continue to bloom even in the most intense peaks of heat.
A second sowing of sunflowers
Those who have already sown sunflowers in spring can take advantage of July for a second round: many varieties ripen in 60-80 days, giving fresh blooms later in the season. Staggered sowing allows flowering to be extended until autumn.
Warm climate vegetables and herbs
Heat-loving crops can be productive even if planted in midsummer. Peppers and okra are among the best choices because they are well adapted to heat and dry soil. Basil is also a great option: in many gardens it even performs better in the warmer weeks than in spring.
Four tips for planting in the heat
If you still decide to plant during this period, the timing and subsequent care make all the difference.
So, is it too hot to plant?
Not necessarily, if temperatures steadily approach 35°C, it is better to postpone large landscaping projects, new lawns and more expensive shrubs until a cooler season. But by choosing the right plants and giving them extra care, there is still a lot that can be successfully planted in July. The secret is to work in harmony with the climate rather than against it, reserving the most demanding interventions for a more favorable season.
