We experienced one of the hottest and driest Junes in recorded Minnesota history. Meteorologists predict that the record setting hot temperatures will continue for the summer along with an extended period of dry weather. We have been in drought conditions now for several weeks. Wells are becoming depleted and some cities are issuing watering schedules or outright bans.
Fortunately for us in Camden we get our water from the Mississippi, and so we have not had any watering bans issued in the city – yet. Without rain even the Mississippi can experience low volumes and if this should occur we may be faced with limits on watering our yards and gardens this summer. Water is a precious resource needed by all living things; humans, animals and plants. We are using our precious treated water to provide for our plants, so we need to water wisely. Knowing when, where and how to water our gardens, trees and lawns is a key to growing healthy plants and conserving our precious water supply.
We need to keep our plants watered. Water stressed plants will grow slower and may even have a hard time surviving the winter. In the case of fruit crops (apples, raspberries, strawberries etc.) stressed plants will have a lower yield, smaller fruit and slow plant growth.
How much to water will depend on a number of factors including soil type. Sandy soils hold less water and may require more frequent watering than heavier soils, such as clay or loamy soils. A rule of thumb is that a garden or lawn needs 1” of water per week, but it is hard to determine what that means. Considering a 10’ x 10’ area, that translates to 62 gallons per week (8 or 9 gallons per day) or for a 4’ x 8’ raised bed 20 gallons per week. If you are watering with a hose you can calculate how much water you are delivering to your plants by filling a container of known volume (5 gallon bucket or 2 gallon pail) and calculating the amount of time it takes the container to fill. That way you will know how much water your hose delivers per second or minute. In hot weather, greater than 90° during the day and 70° at night, you may have to water daily or every other day, because of evaporation.
Potted plants may require watering every day. Stick your finger six inches into the soil in the pot and if it is dry, it needs watering. No matter how often you water or what method you use be sure to water long and deeply to encourage deep root growth. That is another advantage to planting native plants. Over time they develop deep root systems that make them more drought tolerant.
Watering wisely means to deliver water to your plants in the most efficient and conservative manner.
- Water the soil not the plant. The plant takes up the water through its roots. The use of soaker hoses or drip hoses is an efficient way to do that. (It is also easy as you don’t have to stand with the hose for hours making sure the soil is sufficiently soaked.)
- Water early in the morning. This will reduce the amount of water lost to evaporation in the heat of the day. If you have to water in the evening, be sure to keep the water off the leaves to reduce the chance of foliar disease.
- If you water by hand, water the soil at the base of the plants and allow the water to soak in deeply, again timing how much water you are delivering to the plant per minute.
- If you must water with a sprinkler use one that sprays low to the ground, again to reduce evaporation. You also want to keep the water from blowing away and deliver it to the soil and not the leaves.
- Soil covered with mulch will retain moisture longer than bare soil so you may have to water less frequently. Use organic mulch such as wood chips or shredded leaves.
Lawns require a lot less watering than we think. Most of the grasses in our home landscapes are the type that will go dormant in extremely hot weather and green up again once it rains. Trees, however, need more water than we probably think, especially newly planted trees. The root system of newly planted trees whether they were bare root, balled or burlapped are very restricted. It can take one to two years for the root system to become well established. During this time it is very important that they receive regular watering. In the first two weeks they need daily watering, for the next three to 12 weeks they need watering every 2-3 days, and after 12 weeks they need weekly watering. This applies to trees you plant in your yard or trees planted on the boulevards.
If Minneapolis Forestry has planted a new tree on your boulevard make it your responsibility to see that it is watered. Most of the time you will see a treegator around the tree. Treegators are green bags that hold water and slowly release it in to the soil over five to nine hours. The treegators need to be refilled every five to seven days, but with over 600,000 trees to take care of in the City of Minneapolis it is nearly impossible for the Park Board to keep all of the treegators filled. Make it your civic responsibility to keep any newly planted trees watered near you. After all we are the one who directly benefit from the urban canopy providing shade and reducing carbon in the atmosphere. To refill a treegator look for the fill hole at the top of the bag. If water pours out you are filling through the wrong opening. Fill about ¼ full, lift gently by the handles at the top and then fill to the desired level. Your efforts will be appreciated for generations to come.
Now, please excuse me. I have to go out and lay my new soaker hose.
To care for the living earth is to care for ourselves.