It only takes a little observation to conclude that each garden has a number of microclimates. Walls, hedges, mounds, shade, the presence of a watercourse or windy corridors modify the general climate perceived in the area. Learn to identify the microclimates of your garden to make the most of them!
Visible natural clues
The temperature is rarely homogeneous in all areas of a given garden at a given time, and for good reason!
- You have undoubtedly noticed, if snow has ever fallen in your garden, that some areas melt much faster than others. The same goes for frost and frosting, which are often more present in a particular area than in another. These clues are valuable in determining which areas are colder and which are warming up faster. You should therefore avoid installing the most frigid plants in areas where snow and frost have difficulty melting!
- On a mound or slope, the soil dries much faster. This is due to the flow of water on the slope, the soil is naturally better drained. You will therefore plant plants that prefer not to have stagnant water at the roots, such as irises, which will stabilize the mound, and many other bulbs, as well as xerophytic and Mediterranean plants.
- Leaf piles are also interesting clues to the prevailing winds in your garden. Where they are constantly swept up, you will not plant wind-sensitive or gelatinous plants. Why frosty? Because there is a difference between the temperature under cover (the one predicted by the weather forecast) and the temperature felt, which can drop by several degrees depending on the wind. In very windy areas of the garden, it will be necessary to take this parameter into account without necessarily launching into prohibitive calculations. It will be enough to prefer the zones where the dead leaves remain in place on the ground to plant your most fragile plants.
- Puddles are interesting in many ways! Where puddles have difficulty disappearing, you can bet on a clay soil that is compatible with certain plants, but certainly not with plants that fear excess humidity! They can also indicate a soil compacted by constant work or a concern for drainage. The only thing left to do is to develop the area or take advantage of it to plant plants that appreciate these conditions!
- Trees that lose their leaves naturally (deciduous) also offer a very special area in the garden, as it is shaded in summer and in full sun in winter. This type of area is suitable for many perennials and shrubs that need shade in the summer to protect them from burning, such as camellias, rhododendrons, or hydrangeas, but also for spring bulbs that will benefit from the winter sun to develop at their best. A quick aside for our beekeeper friends: bees will also appreciate this type of sunny place in winter to warm up the hive and shaded in summer for a better comfort!
- The evergreen trees will offer an ideal cover for the less hardy and shade tolerant plants because frost is much less severe in an undergrowth than in an open meadow, think about it! They will be able to shelter many plants that appreciate partial shade, such as periwinkles, cyclamen, ferns, magnificent black-leaved ophiopogons, euphorbias, foxgloves or even heuchers and pulmonaria!
More technical tips
- Thermometers that allow for a daily reading of the highest and lowest temperatures will be placed in various areas of the garden on the same day for 24 hours. You will probably be very surprised at the wide variation in your readings depending on the areas of the garden tested. Repeat the operation several days in a row to draw your conclusions and plant accordingly!
- The same experiment can be done with rain gauges and you will notice that under some large and bushy evergreen trees, water reaches the ground more difficult than in open areas. It will then be appropriate to consider plants that tolerate not only shade but also a rather dry soil in these locations.
- Hedges are very particular zones in the garden, because they certainly protect from the wind, but they can also be victims of turbulence just under their foot. Depending on their constitution (bald or not, deciduous or not...) they slow down the wind, filter the sun and regulate the hygrometry rate in the air. The temperature differences are less obvious in the presence of hedges than in the opposite case. Water evaporation from the soil is also less in relation to a bare area. All these combined effects have always been appreciated to increase the yields of crops by market gardeners and this, until the dismemberment, but this is another story ... You can therefore plant more fragile plants or install your vegetable garden not far from a hedge. If possible, keep a distance equal to half the height of the hedge to avoid the turbulence sometimes present at the foot of the hedge as well as the competition of the roots. You can also plant plants that are sensitive to breakage, such as large dahlias, gladioli or peonies.
- Along the walls, the temperature can vary greatly compared to an area left bare in the garden. This type of construction stores energy and releases it at night, especially if the wall is facing south! Beware, not all plants will resist, especially in the south! Install your cacti, bougainvilleas, Yucca or plants requiring a lot of heat in this location!
In the case of a wall exposed to the north, the situation is quite different! Shade and coolness reign supreme, moss grows vigorously and humidity is present. It is the favorite domain of ferns, begonias and impatiens in summer, but also of hostas, periwinkles or pulmonaria which will find all the favorable conditions for their growth there!
