Preparing the Garden for a Hot Summer

Here in the Pacific Northwest, we have had record high temperatures already this spring. When the temperature is 100° F in spring, it is HOT!  Not that our weather pattern is ever predictable, but this year it seems to be even less consistent. With our mild winter temperatures, record rain, and a summer forecast as being hot and dry, our plants may suffer without some additional help.

In my own garden, I have become more aware of the need to get the right plant for the right place. What that means is that for full sun I make certain that I have a plant that appreciates this exposure. When we have temperatures in the triple digits, our soil can dry out very quickly and plants may suffer. While I realize that most gardeners have probably planted most of their containers and the bulk of their annual flowers and vegetables, we can still amend the top layer of soil to benefit the plants.

Amend Shrubs

Hydrangea Snow Queen
Hydrangea quercifolia ‘Snow Queen’ (oakleaf hydrangea) stands up better in the heat.

I have learned that some Hydrangeas are especially prone to suffering in hot weather. One of my favorites is Hydrangea aspera, which is a tall shrub. My plant is over 8 feet tall. It has such beautiful flowers that it is a showpiece in the summer garden. However, on hot days, the leaves will wilt as though it has not been watered for days when the soil is in fact moist. I recently added Black Gold Just Coir to the soil surface and worked it into the upper 1-2 inches of soil and this has helped. On the other hand, my Hydrangea quercifolia ‘Snow Queen’ (oakleaf hydrangea) stands up better in the heat.


Amend Vegetables and Flowers

In the vegetable garden, this is an ideal time to add Black Gold Just Coir or Garden Compost as either of these will help to hold soil moisture. June is the month many gardeners plant basil, and it is often planted in containers. In our garden, we always have a container of basil near the kitchen, and I use Black Gold Natural & Organic Potting Soil with RESiLIENCE®.

While many annuals may wither in the heat, an excellent summer bloomer is Lantana camera. While technically a tropical shrub, it is usually treated as an annual here. It thrives in the heat, blooms constantly, and the flowers attract butterflies. Lantana makes a wonderful container plant on a deck or patio because of the continuous bloom.

For the past few years, a signature plant in our garden is the red leaf banana, Ensete ventricosum. It has gorgeous large, red leaves and while a tropical plant, I have mine in large pots in a full sun location, and they do fine. My choice of soil is Black Gold Natural & Organic Potting Soil, and it seems to hold adequate moisture for these plants. A special treat that the red leaf banana provides is that by watering overhead, where the leaf meets the trunk, a small pocket of water will accumulate. This has become a very popular home for frogs to the delight of grandkids.


Water Regularly

Lantana, colors
An excellent summer bloomer for heat is Lantana camera.

When we have very hot days, and I see wilted plants that I know have adequate soil moisture, I will often spray them with a hose. This additionalwater seems to perk them up and within a period of less than an hour, they are looking fine.

Be aware of your plants and their environment and try to imagine where a favorite garden plant might naturally grow best in your yard. Don’t get too stressed if your plants wilt, take precautions, and then enjoy them, your garden, and the summer.

Mulching Gardens With Black Gold Amendments

When the drought is long, soils are poor, and money is short, one way to revitalize struggling garden plants is to protect their roots with mulch. Good mulches help to retain moisture, cool the root zone, and discourage weeds. The conventional wisdom is to mulch with wood chips or ground up bark, but both are very slow to decompose and can bind needed soil nutrients. The better option is to protect small beds and containers with organic-rich amendments that give back.

Garden Mulches for Soil Enrichment

Rich compost, peat moss, coir, or Black Gold Earthworm Castings are all amendments that double as mulches–alone or as home-mixed blends–in small ornamental gardens or vegetable gardens.  All offer needed organic matter, which helps soils better retain water and maintain porosity. They also offer structural and water-holding benefits.  For example, Black Gold Garden Compost Blend contains peat moss for water retention and compost give poor soils better aeration for easier establishment and performance.

Amendment mulching is often most effective in shaded areas because it helps to simulate conditions on the forest floor.  If you take a cross section of this “duff” layer, you’ll see that it’s mostly leaves or needles with a fine, dark layer that sits right on top of the earth.  It’s rich in decomposing organic matter, which is why shade plants are often surface rooted.

Landscape Mulches for Trees and Shrubs

This is also true of acid-loving plants, such as azaleas or camellias, which  develop a wide, shallow root system where the majority of the soil nutrition lies. In fact, without a yearly surface application of organic matter, these plants can suffer. All too often you see the surface roots of azaleas exposed after years without the addition of a mulch layer.  The organic matter is essential to keep their roots moist and cool, especially when drought descends. We recommend mixing a 1:1 of Black Gold Garden Compost Blend and Black Gold Peat Moss for acid lovers. Both products offer needed organic matter and peat moss is a little more acid, which benefits these plants.

Assess your favorite plants, planters, individual trees and shrubs to determine if they will benefit from this special treatment.   Apply a 2- to 3-inch layer of amendment around the base of the plant.  Always keep it few inches clear of the trunk to prevent bark-to- mulch contact, which can induce stress and rot.  Extend the mulch layer out to the edge of the drip line.

Don’t work the amendment in. Just smooth and pat it with your palm to flatten it out for better soil contact.   Moisten often with just a light spray or collected household water to keep these amazing shrubs and trees happy on minimal rainfall.  For areas with brief drought, mulch provides great short-term protection from an abnormally dry or hot summer.

As landscapes everywhere are being altered to be more efficient, don’t forget that amendment mulch can mean so much more to your plants.  If you already have bark mulch in place, the next best thing is to sprinkle amendments over the bark, so they can filter down and provide support the next deep water day or after a welcome summer cloudburst.