Gee… Wonder Why We’re Waiting to Plant Annuals

May Day at tea time.

May Day at tea time.


The average last frost date in Colorado Springs is May 15th. That means we might see five years with no frost after May Day, another year with the last frost on Cinqo de Mayo, and then — whoops, look out — a frost on the last day before June.

Many “old timers” never would plant annuals outdoors until after that first weenie roast over Memorial Day weekend.

I’ve even heard tell of a Mother’s Day blizzard.

So hold on to your posies and tomatoes. Even if the frosts are over, the ground is cold and the nights are chilly. One colloquial favorite of mine: Put out tender plants when the new oak leaves are the size of a squirrel’s ear.

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For the Time Being

For most of us, winter watering means dragging a hose.

For most of us, winter watering means dragging a hose.

It’s still devastatingly dry. In oreder to keep plants, shrubs, lawn, and soil alive in your Eastern Colorado landscape, you’ll more than likely need to water.

Here are some tips:

  • The best way to know if you need to water, is to poke a blade six inches into the soil, open a wedge and feel it. If it feels moist or is frozen, no need to water.
  • Check your soil at least every three weeks.
  • Don’t rely on a little bit of snow to do the trick. It often takes 10 inches of snow to equal one inch of rain.
  • Water when the temperature is above 40 degrees.
  • The best hours of the day for watering are usually between 10:00 AM and 2:00 PM. However, on very warm days, that window may be bigger.

Your neighbors, your wife, or your best friends might ask, “Why are you watering? Everything’s dead!”

That’s a perfect time to shine your intelligence. “They’re not dead. They’re dormant.”

There’s a big difference, and you know it.

Why Wait for Fall

I first discovered fall planting about a decade ago. How? Springtime is too busy to plant in my own garden while keeping up with client demands. Summer? Well, it’s just too darned hot for both the planter and the newly planted.

Great things happen after the first of August, however.

First, nights get longer and generally cooler. This means that even if the day is hot, there’s often a respite between dusk and dawn — for garden and gardener alike. Longer, cooler nights help keep moisture in plants and soil. Stress levels go down.

Near the beginning of September, nights have become long enough to trigger changes in plant processes. What we notice takes place above ground — greatly diminished growth, the yellowing of some leaves, and a mellowing and quieting of most blooming activity. What we can’t see: Below the surface, roots are growing.

Growing underground in September, this new installation will start filling in next spring.

The convergence of lower overall stress and root growth make for excellent planting conditions. There is less opportunity for transplant shock. Even better, there is a good chance the new plant will root out in the still-warm soil creating a stronger plant next spring.

Another advantage of fall planting is cost saving. Garden centers regularly offer great bargains to clear their shelves. And, because it’s cooler you won’t be spending as much time and money keeping new plants hydrated.

Most plants benefit from dividing, transplanting, and planting in the early fall — from mid-August to the Autumnal equinox. This includes irises, daylilies, perennials, ornamental grasses, deciduous and evergreen shrubs, and small trees. Some sources say that grasses and evergreens do best if planted in the spring, but I can’t say I’ve found that to be true. Trees may also do quite well if planted after they’ve dropped their leaves in October.

You’ll want to get all your planting done by October. Not that all your plants will turn into pumpkins after October 1. It’s just you’ll want time to put in bulbs for spring.

Speaking of bulbs: Have  you placed your orders?

When It’s Too Darned Hot: Tasty Soil, Tender Mulch, and Just Enough Water

Have you felt yourself wilting, lately?

A day in the nineties or triple digits, makes me glad I’m a mobile creature. I can retreat to the shade or the relative cool of an interior. But what happens to plants when the temperatures soar?

Plants, like people, differ in their responses to heat.

As you can imagine, plants which evolved in steamy tropical rain forests and searing deserts survive the heat without much apparent fuss. It’s the plants from temperate zones which stress and cause the gardener to stress even more.

Like afternoon naps for the gardener, one of plants’ heat survival strategies is dormancy. A great example is the natural response of bluegrass varieties. When the heat turns up, bluegrass turns brown and goes to sleep. The water we pour on it through the hottest months isn’t so much to keep it alive, but to keep it cool. As long as irrigation water is evaporating and cooling the lawn, it stays relatively green. According to University of Colorado Extension, a healthy bluegrass lawn can get by on twice weekly irrigation and can survive in dormancy for weeks or even months without irrigation. Once cooler temperatures return, begin regular watering, and the green will follow.

Many flowering annuals take a break in the heat. While they aren’t totally dormant, they save their energy for the opening and closing of stomata, a kind of pore on the undersides of leaves. Perennials that normally bloom in summer’s heat, such as lilies, may wrap up their season in a hurry. When a plant wants to rest from the heat, it’s important to refrain from fertilizing. This is especially true of roses.

The Golden Jubilee Agastache pictured above is in a serious heat wilt. It is also more sensitive to soil moisture than many of the plants around it. I call it a signal plant. When it droops, I watch it as the evening cools. If it perks up, soil moisture is not yet an issue. If it doesn’t, you’ll see a sprinkler out in the morning.

During a heatwave, the natural impulse of many a gardener is to turn on the tap. While it’s important to keep garden soils from drying completely, we often water more frequently than necessary. In sandy, porous soils, three times a week might suffice. In clay-based soils, twice a week could do it. The trick is to irrigate for longer periods during extreme heat, making sure moisture penetrates to a depth of 6-8 inches.

To muddy the waters a bit: All watering rules are relative. How quickly do the temperatures rise in the morning? How far did they go down overnight? What is the relative humidity? Has it been windy? Any of these factors can change your watering regimen.

Knowing when to water is told by the soil. Put a blade in to a depth of 3-4 inches and make an opening. Feel the soil at the bottom of the opening. If it is cool and damp, all is more or less well. If it is dry, it’s time to water. Relying on plants to tell you when to water can be misleading. While it’s true that plants droop when they need a drink, they also droop in heat. They can also droop from drowning.

The same principles apply to the vegetable garden. According to University of Colorado Extension, a properly prepared veg garden should be able to tolerate intervals of 2-7 days between watering.

These watering intervals might seem counterintuitive at best, preposterous at worse, but the key is to follow other practices as well.

The foundation to any lawn or garden survival through these conditions is living soil. Soils that are properly amended save on water and support stronger, more resistant plants.

In addition, the use of mulch is crucial, even in the veg garden. The goal should be no exposed soil surface. Even half an inch of humus, leaves, straw, or fine gravel will shade the soil, helping to keep it cool and reduce evaporation.

Timing and delivery methods of watering are also important. Most experts agree: water in the morning and deliver the water at the soil’s surface, under the mulch, if possible. This helps mitigate fungal and disease issues as well as conserve water.

Keeping up with watering is sometimes the only thing a hose-dragger like me can accomplish during the hottest weeks. The comfort is knowing that as the day’s grow shorter, longer nights and cooler overnight temperatures give both gardens and gardeners a much needed respite.

Iris

It’s iris season. While some take prized positions in well-planned perennial borders, other tall bearded iris spangle parking medians, flash out of gravel wastelands in neglected foundation beds, march along driveways.

Iris shares its name with a Greek goddess of the sea and sky. In mythology, she is a messanger, able to travel from the underworld to the heavens and is associated with the rainbow. She brings water to the clouds. The water she carries is also poured on those who perjure themselves, putting them to sleep. Here she is depicted in Morpheus and Iris, an 1811 painting by Pierre Narcisse Guerin.

As a member of the garden pantheon, Iris has a lot to recommend her. Irises generally require little care, are long-lived, and multiply easily. And who can quarrel with the immense variety of color they offer?

Iris do best in full sun, and prefer a neutral, well-draining soil.

They perform best on a lean diet. A low-nitrogen fertilizer may be applied when bloom stalks appear and about a month after blooming.

Iris should be divided every 3-5 years. The best time to divide is right after blooming.

Remove dead leaves and spent bloom stalks, but don’t compost them. Leave the rest of the fan standing, as the greenery feeds the rhizome.

OK, it’s true: the bloom season is short, especially if the weather turns brutally hot and windy. A well-planned perennial garden, however, will have something to capture our hearts soon as the iris fade.

The Miserable Gardener , in a blog entry titled “After the Rain,” has written off iris. But even Mr. Miserable makes an acception: Iris pallida. My favorite variety is “Variegata.” The leaves glow all season.

Sage and Savvy, Number One

What’s a gardening website without tips, tid-bits, and to-do lists?

Every now and then, at least, don’t you think?

Some of my favorite tools for Spring clean-up. Especially the little rake. It can get into the crunchiest of places.

Spring clean-up will soon be wrapping up in these parts, but just in case you’re running a little behind, like I am, here’s a couple of tips:

  • Use hedge shears to cut back dead stems and grasses. I find cutting is easier on the plants than pulling, except with daylilies and iris.
  • Cut down a whole bed at once (unless it’s too windy), and then rake it off.
  • Toss everything directly into a large trash can or open tarp that drags along as you progress through a bed.
  • Compost at home, or take winter’s dregs to a place like our beloved Rocky Top for recycling.

Gotta love a hori-hori.

Now is a great time to:

  • Blade out those cool season weeds, like dandelions.
  • Get soil activator and fertilizer on what’s left of your lawn.
  • Scatter, scratch, and water in compost or organic fertilizer around your shrubs, grasses, and perennials.
  • Turn on your irrigation system or start dragging hoses.
  • Top off your mulch.
  • Cut new edges along beds and walkways.
  • Pinch back those geraniums you overwintered.
  • Resume the stretching you ignored all winter long.
  • Stock up on sunscreen.

Oh, and if you have early season tulips of daffodils that have finished blooming, snap off the seed pod forming at the tip of the stem. Bulbs tire more easily if they bear seeds.

Always remember to step back from time to time and admire your work.

Oh! Oh! And one more thing: Schedule a massage.