Homegrown: Watering in the fall
Earlier in the season, I was advised that we should be watering our lawn/trees two times a week for 45 minutes, which was very good advice.
Now that fall is here, how should we scale down our watering schedule until shutdown of irrigation water in October? Does temperature have an effect on fall watering? Always appreciate your advice.
Your instinct is absolutely correct. It just makes sense to water less as the weather changes. Plants don’t require as much water this time of year as when it was blazing hot in July.
However, there’s another thing that factors into our watering schedules. This time of year we want our landscape plants to start thinking about going into dormancy for the coming winter.
With some plants, continuing to push lots of water (and fertilizer for that matter) will stimulate them to continue growing later into the fall where early frosts can damage or even kill them.
Obviously, you don’t want to injure the plant due to lack of water, but you do want to “push the envelope” a bit this time of the year.
I’m afraid I don’t have any hard and fast rules about how much to water and how often to do it. There are just too many variables, but you want to continue to water deeply and thoroughly when you do water. You just need to vary how often you water in response to what the weather is doing and how your plants look.
Like most people I have an automatic sprinkler system at my house. What I do is to suspend the program and wait until I think it’s time to water again, and then I’ll either manually start the sprinklers or just put it back on its programmed schedule.
I guess the key is just to keep an eye on the yard. I take a quick peek every day or two and look for plants that are just starting to show a bit of stress.
This may be some minor wilting or sagging of a particular plant, a change in color, leaf luster or overall appearance.
Now, I can hear you thinking, “for crying out loud, I have NO IDEA what to look for!”
This takes some time to master, but observing the yard is the beginning point. You’ll begin to recognize how things should or shouldn’t look and when the lawn starts looking dull or off color or a couple of perennials in that hot, sunny spot start to droop a bit.
Those are clues that it’s perhaps time to water.
I use plant appearance as the first step; the definitive test about whether to water or not is to check the moisture level of the soil. I’ll go out with a shovel and dig down nearby and verify that things are starting to dry out enough to justify watering. Now, I don’t need to continue digging week after week and year after year. Once I’ve established a correlation between plant appearance and soil moisture, I’ll just watch the plants.
I know that this is all a bit nebulous, and we all want hard and fast rules, but I’m afraid I just don’t have any.
Should I trim the irises after they bloom? Also, I put some weed barrier around the plants but maybe this is a bad idea if I want them to spread and fill in the area?
Some people advocate cutting the fans of foliage back by one third to one half in late summer.
Personally, I let iris go until the foliage freezes down in November and then remove it.
I would cut a good hole in the weed barrier fabric. They do want to grow and spread over the years and you want to accommodate that to an extent.
If you want them to fill an area, they you should definitely cut the fabric out in that area.