This will be our last installment on gardening in drought conditions (for now), just a few final points.
Although we’ve experienced a pretty heavy drought in the Chicago area this summer, in any given summer (and for that matter any given garden), there are times and areas that require drought tolerant plants. If you want plants that will hold up under lots of sun and can manage low watering maintenance, consider planting succulents (plants with very fleshy thick leaves that hold a lot of water) like Sedum (stonecrop), Delosperma (ice plant), or Sempervivum (Hens and Chicks). Other plants that like sun and dry conditions are Russian sage, lavender, and Walker’s Low catmint.
When you transplant or install any plants, fill the hole you dig with water and make sure it drains in a reasonable amount of time (one inch of water in a six inch wide wet hole can take anywhere from 15 to 60 minutes to dissipate, if your drainage is adequate). If the water does not drain it indicates that your soil won’t offer good drainage to a plant in general. Be aware of this because too much water can also kill a plant (we will address this point in future posts since you may want to consider amending your soil). Once the plant is installed, make sure you cover the area with at least two inches of fine leaf mulch. The mulch keeps the water from evaporating, keeps the soil moist, and over time adds needed botanic material back into the soil.
Here’s a picture of the Sedum in our yard. This picture is earlier this year. See how cracked and dry the soil is and the plant is still green and healthy. This particular variety blooms full reddish color, almost balls of flowers. A nice addition to a garden.
Here is a picture of our back yard taken on July 22, 2012, after weeks of drought conditions in Chicago. We water as noted in the previous post (make sure you check that out) and you can see that the lawn and garden are green and healthy. Notice the difference between our yard and the area in the top left portion of the picture which is not watered regularly.
So this is the next installment of Gardening in Drought Conditions.
I thought some additional information on watering might be helpful. Let’s say its 75 degrees outside-go with me on this…we loose about an inch of water a week at that temperature, so we would need to give back an inch of water a week, either through rain or watering, to keep established plants pretty healthy.
So how do we know what an inch of water is? To monitor this put out a rain gauge. You can get a really fancy wireless gauge that has lots of buzzers and bells at Home Depot. I use the caveman version, a cat food can. The idea is to leave the receptacle out in an area that is getting rain or sprinkler water so you can measure how much is distributed over a period of time. Make sure the receptacle is in a place that gets an average distribution of water so it’s a good estimate of what is falling on the entire area. If you are watering an area that has lots of plants put the receptacle on the ground under foliage to measure the water actually getting down to the ground and not just on the leaves.
We put out a traditional arcing sprinkler, the kind we used to run through when we were kids. It arcs a full 180 degrees and we leave it on for an hour or so on the lawn. We find that this gives us about a 1/4 inch of water. This means we would need to water for 4 HOURS to replenish the water loss over the course of a week. (It’s ok to soak the ground once a week so the water penetrates deeply.) Every yard and every hose is different so use this method to determine what works for your yard.
So that’s at 75 degrees, a lovely temperature. If the temp goes up the water loss increases…for every 10 degree increase in temperature the water loss increases by 1/2″. So at 95 degrees it’s 2″ of water that needs to be replenished. So we would leave our sprinkler on for 4 hours twice a week, pretty easy math. This is doable in most areas so we can have healthy gardens even in this weather.
So in summary at 75 degrees replenish 1 inch of water a week, for just about everything. If you have non-native trees they need more like 2″ per week. If the temp goes up 10 degrees the additional water needed is 1/2 inch. Newly planted materials need more water more often so always check the roots and the soil to make sure it is moist.
Any questions let me know!
btw-next post will be plant ideas for drought conditions.
Recently I was asked, “How do you garden with these high temperatures and drought conditions?” For existing gardens suffering under this brutal heat, you can save your plants with the proper watering. Even if you have watering restrictions you can give them enough to get them through these hot days.
Any plant that is visibly wilting will want a gentle stream of water at its base for several minutes, up to even an hour if needed. The goal is to soak the ground around and deeply under the plant keeping the roots moist and prompting them to search for water deeper into the ground where they are more likely to find sustaining moisture.
Maintenance watering for large plants and shrubs should be focused at the base of each plant. Use a hand held sprayer on a “shower” setting that does not disturb the dirt, but allows the water to collect and penetrate into the ground at the base of the plant. You may need to make repeated applications to insure enough water has made it into the ground. If you use a sprinkler, leave the water on long enough to soak deeply into the ground. In either case, if water starts to pool and run off stop the flow, let the water soak in, and turn the water back on for additional watering.
The goal whenever watering is to make sure the ground around and under the root ball of the plant is wet. Whenever there is uncertainty as to whether enough water has been applied, use a trowel or shovel to gently dig into the soil at least 3-4″ to check if the soil is moist. If not, you need more water.
Water plants early in the day so the leaves have time to dry. If you have time restrictions, you can set timers to allow the water to run even when you can’t hold the hose. If you are limited to certain days for watering, make sure you apply enough water to keep the soil moist during your off days.
These are general techniques. If you have specific issues, questions, or needs, please leave a comment and I’ll offer any help to your garden I can. I look forward to hearing from you.
btw – In the next post I will include some specifics on water requirements and application for various situations.