Rose Watering

Watering Roses and Irrigation Considerations

David Candler

How much, how often?

1 inch (equivalent rainfall) per week from nature or hose.
For a 12 inch radius circle around each plant (area= 12x12x3.14159)= 452 sq. in.
For 1” of water (deep) this is 452 cu. in.
Since there are ~ 7.5 gal. per cu. ft. (1728 cu. in.),
therefore you need 2-3 gal. per bush minimum per week.
Better if done in large doses, not sprinkles

Difficult to overwater plants in the ground if the soil is rich sandy loam, in CT
(unless you have very high-clay soil, and dig small planting holes)

Easy to underwater, especially if:
    You have mostly sand, and little organic matter in the soil
    You have recently fertilized with chemical fertilizers (salts)
    It is hot, windy summer
    You have little mulch to keep the ground damp and cool
        Or… you didn’t water

Where to water?

All around the rosebush- out to the extent of the roots- roughly branch spread
Not in a single drip spot- especially in sandy soil
Think 3D, the water needs to get to the entire root region- so water deeply
Avoid loss by evaporation

When to water:

Water the roots, not the leaves. If you do overhead watering, be sure you do early- and ensure that the leaves will dry by evening, and not foster fungus. Avoid splashing the water up from the ground to the leaves- thought to spread Black Spot. Thus, use a low velocity nozzle rather than a hard spray to reduce splashing.
Soluble fertilizer can be added to the water for a consistent nourishing of the plant, but beware to do the math properly: don’t make the solution too concentrated.

Drought considerations:

More mulch
Save and use rainwater and clean house wastewater
Avoid strong fertilization if you cannot water prior and after-
If only a few roses, or if potted, consider adding Soil Moist to the soil. This product absorbs water, when in excess, and slowly releases.
Pots to semi-shade if heat and drought is severe, and you cannot water
Use the systems discussed below

Alternatives to the hose:

Soaker hose- multi-porous

Sometimes called by a Product Trade Name "Leaky Pipe".  Usually made from old automobile tire rubber.  Does not have actual holes, but is porous by construction technique.  Slow rate of flow, about 2 liters per meter of hose per hour. (So if your planting has one HT per meter, and if you figure 1/2 of the water is close enough to each stem to be useful, then that's about 1 gal. per bush in 4 hours.  So with no additional rain to help, you would need to leave running about 12 hours to gain 3 gallons (equals about 1" of rainfall).
Slow, but covers a large, linear area. Most cheap hoses are inferior, and sprout leaks readily. A Quick solution. Reasonably inexpensive. Last 2-5 years. Can be placed on top of, or under mulch. Can be chained. DO NOT use full water pressure. Best if garden is approximately one level (not up or down hill). Can set and forget and go to work- no need to tend in a few hours. Good for preventing dry out, but best used to complement a hose about weekly.
When selecting a hose to water your roses, try a soaker hose, or another type that provides water only around the roots; overhead watering can damage rose blooms with spots and fungal diseases.

A link: http://www.1st4irrigation.com/1st4_LeakyPipe.htm

 

Drip line

Come in several versions related to size and frequency of emitters. One emitter per foot is Not enough. Every six inches suffices, but a good size bush will perhaps need the pipe strung down one side of the row, and back on the other side of the plants. Must be ‘on’ for a significant time. Best if the ground is level. Easy setup, and cost is reasonable. Very flexible, and can be adapted to any size garden. Use only ½” or larger line.

Poly tubing with dedicated ¼” drip circles

Very good water distribution. Somewhat more work, but straightforward. Very adaptable to unusual size/shape gardens. Easy to see the results. Adding a bush can readily be accommodated. Errors or plant removals can be undone. Inexpensive.
 

Poly tubing with dedicated emitters

Excellent water distribution. Good flow-rate (up to 15 gph), so that time to complete watering can be relatively short (and unattended until turnoff time). Reducing the hose pressure can slow the rate, so that can be left to run all day (e.g. while at work). Takes the place of hose watering instead of being a complement to that method. Not expensive. Some simple work to assemble- about 3 minutes per rose.

All the major watering and irrigation systems appropriate to roses are available at one source. Information and shopping around is Much Easier!

Good Information:
Dripworks
www.Dripworks.com
Catalog Request Line: 800.616.8321

Competitor:
Submatic Irrigation Systems
www.submatic.com 
800.692.4100

And don’t forget, call:
CT Rose Society Consulting Rosarians
And our website
www.ctrose.org