Tag Archives: microclimates

The Dog Days of Summer

Swallowtail butterfly- a regular summertime visitor.

They’re called the Dog Days of summer. You know, those sultry days with the hottest summer temperatures. The name “dog star” comes from the ancient Egyptians who called Sirius, the dog star, after their god, Osiris. His head in pictograms resembles that of a dog. When the Dog Star rises in conjunction with the sun some felt the combination of the brightest luminary of the day – the sun – and and brightest star of the night – Sirius – was responsible for the extreme heat experienced during the middle of the summertime. Since Sirius is the brightest star in the night sky it’s reasonable to guess that it adds some heat to the earth but the amount is insignificant.

The Romans associated the hot weather from 20 days before to 20 days after the conjunction “the dog days of summer” because it coincidentally fell at the time of year when it was very hot. This falls between July 24th and August 24th. The Old Farmer’s Almanac uses slightly different dates but the Dog Days of summer are definitely here.

We now know the heat of summer is a direct result of the earths tilt, but now you know… the rest of the story.

As summer rolls along you may become more aware of the different microclimates in your garden. With the drier and hotter weather this year, some of your plants that used to get along just fine might be showing signs of stress. Taking note of these changes in the performance of your plants is what makes for a more successful landscape. When the weather cools towards the end of September you will want to move or eliminate those plants that aren’t thriving. Be sure to keep a thick layer of mulch on the soil around your plants to conserve that precious water you do allocate to each of your irrigation zones.

One thing I notice when I visit gardens for a consultation is the existing drip system has not been modified for many years, if ever, to allow for the growth of the plants. The emitters which were originally placed at the base of each plant are not even close to covering the current size of the root zone. The crown of the plant is getting overwatered with each cycle but the rest of the plant is bone dry. Time to add more emitters and move them away from the middle of the plant. No sense wasting water that’s not doing the plant much good.

Add the soothing sound of wind chimes to your summer garden.

The dog days of summer may be affecting our gardens but it doesn’t have to stop us from being out in the garden. . The joy of gardening can take many forms including adding a wind chime, bird feeder or bird bath. Groom plants that need some cleanup. Many perennials benefit from a little haircut at this time of year to extend their blooming into the fall season. Santa Barbara daisies fall into this category. Lavenders will keep their compact shape by pruning a third of their branches now. This forces new growth in the center so the plant doesn’t get woody.

Deadhead flowering annuals and perennials as often as you can. Annuals like marigolds, petunias, zinnia and cosmos will stop blooming if you allow them to go to seed. The same is true of repeat blooming perennials like dahlia, scabiosa and lantana. These plants know they’re on this earth to reproduce. If they get a chance to set seed, the show’s over- they’ve raised their family. Try to remove fading flowers regularly and you’ll be amply rewarded.

Swallowtail butterflies are regular visitors to the garden at this time of year. They especially like butterfly bush as well as zinnias and many other flowers. They are easy to photograph if you move slowly.

Microclimates, Rainfall and Pests

Gardening in our microclimates might be challenging and it’s no different here in Maui. Yes, despite the balmy weather, the rainfall here limits what plants thrive. You can drive 5 minutes from an area that receives 400" of rainfall per year to another spot 10 minutes away that gets only 19" per year. Then drive another 15 minutes and you’re in a desert-like area with annual rainfall of 10" while the east side of the island, in Hana, is getting 83 inches.

Gardeners in Maui in several ways just as we do. One way is to grow the right plant in the right place. For example, at 4000 ft elevation near the volcano, 55,000 lavender plants  of 45 varieties grow happily in rocky soil. Olive trees – brought over from Santa Cruz – dot the fields. Interesting to note that the lavender plants provide a natural pesticide against the ants that invade the protea flowers. Proteas do well here. Reminded me not to miss our spectacular show of proteas  at the UC Arboretum in April and May. If you’ve never walked through this free garden it’s a treat not to be missed.

If you think all the soil here is of volcanic origin, think again. Of the 12 types of soil in the world, 7 different orders occur here.   The state of Hawaii, as a whole, has 11 types, more than any other state in the United States. By comparison, Maine has only 4 types while the Santa Cruz Mountains has a whopping 9 orders just in our little corner of the world.  Yes, folks, that’s right. No wonder gardening can be a challenge where we live.  What thrives up the road from you doesn’t always grow the same in your yard. Knowledge of soil behavior and nutrients is important where ever you garden.

Maui has a native pea, a native coffeeberry and a native huckleberry just as we do.There is even a native hydrangea although the type we are most familiar with was brought over from Japan in 1790.  Mostly, you see flowering plants introduced from other parts of the world.  Since the 1800’s, people have been bringing all types of plants to the island just like early settlers did to our area. Many of the plants that we commonly grow like the Princess flower ( tibouchina ) and strawberry guava are invasive here. Others like blue plumbago bloom in the drier areas and behave themselves. Gardeners here face the same problems as we do and strive not to dilute the native gene pool.

The rain in Maui is distributed throughout the year which is different than our Mediterranean climate. Before you get jealous, though, this allows slugs, white fly and fungus to proliferate year round. I see mealy bug under most of the plumeria leaves. This intoxicatingly fragrant tree is easy to propagate and grows everywhere on the islands. If you get at least 6 hours of hot sun per day and keep them inside or a greenhouse above 50 degrees at night they will bloom even in our area.

I’ve enjoyed my time in Maui but there’s no place like home.