HG: Homegrown Column March 21, 2009
What is a pre-emergent spray and when should it be applied for fruit trees? Also, is there a schedule for this area for seasonal spraying?
Since pre-emergents control the weed by preventing normal germination, it’s vital that the material be applied before the seed germinates.
The timing varies a bit from year to year depending on the weather, but the particular weed you’re targeting will affect it as well.
For most annual weeds, that’s usually the end of March or the first part of April.
One clue that helps is to apply the pre-emergent when the forsythia are blooming around town. If you’re not familiar with the plant, it’s the shrub with the bright yellow flowers that is about the first thing to bloom in the spring.
Depending upon the weed, you may need to put down a second or even a third application. We usually do this at six week intervals.
Most annual weeds are controlled pretty well with just one application, but some, such as spurge, will need some follow up treatments.
If you’re not sure what it is you have, it’s important to get it identified so you know whether a pre-emergent will even work and how many applications you’ll need to make.
Actually, the common pre-emergents available are pretty much all granular products. They’re much easier to apply, but they have to be watered in after they’re down.
Because you’re applying them before you get ditch water, it means dragging the hose around to give it a good soaking.
There are spray formulations out there, but they’re mostly commercial products, not for the homeowner.
The only other reservation I have is that most all of these products are not labeled for use around fruit trees. In fact, about the only pre-emergent out there I’m aware of that’s labeled for use around edible plants is Corn Gluten Meal.
It’s an organic product and though it helps, you should only expect 40 to 60 percent control of your weeds.
Actually, in the homeowner market, we’re pretty restricted in the herbicides labeled for use around edible plants.
Sorry about the news. Wish I could be more help.
Do anemone bulbs have to be dug up at the end of the summer?
— Donna from Virginia
The answer to your question, it depends on the type of anemone we’re talking about.
There are two main groups of anemone people plant today: the “tuberous” anemones that bloom in the spring or early summer and the Japanese anemones that bloom in the fall.
Japanese anemones are usually planted as a potted plant. They love rich, humusy, well-drained soil and regular water. They’re happiest with a bit of shade.
Here in Grand Junction (which is high desert), they need pretty much full shade because of our hot temperatures, intense sunshine and low humidity. These anemones are hardy to 5–15 degrees below zero.
They usually aren’t dug up and stored for the winter, but putting a winter mulch down in November is beneficial.
We generally think of the tuberous anemones as the “bulb anemones” because they’re often sold as dry clumps with other bulbs such as gladiolus, daffodils and dahlias. There are two common species.
The first is anemone blanda which is also known as Grecian windflower. It’s a lovely small plant that will divide and spread as long as the soil is rich and well drained with ample moisture. This bulb is planted in the fall.
Since it’s native to the Mediterranean region, it will last longer in the garden if the soil around it is allowed to stay on the dry side through the summer.
That’s rarely possible for most folks because they have other plants in the bed that require water. Under these conditions, the plant will survive, but it may peter out on you after several years.
This plant is a bit hardier than Japanese anemone, so it’s not dug up in the fall, either.
The second is anemone coronaria. This is a taller plant with showy single or semi-double flowers in mixed colors (they make great cut flowers) in late spring or early summer.
The two most common varieties you’ll run into are “De Caen” and “St. Brigid.” This species is only hardy to 20–25 degrees above zero, so it’s either grown as an annual and new ones replanted each spring or dug and stored in the fall.