Preventing Mulch Color Wash-Off
The primary cause of wash-off is this: the colorant has not had adequate time to cure on the mulch fiber.
Curing is the actual bonding of the colorant to the mulch and is not to be confused with drying.
Curing can only occur in the landscape setting after the colored mulch has been applied. There are steps, however, that colored mulch producers and retailers can take before that to reduce the possibility of wash-off.
Important curing tips:
- Minimize the amount of water during the manufacturing process — which will reduce cure time.
- Don't ship mulch immediately after it's manufactured. BASF recommends waiting 24 to 48 hours and turning colored mulch piles one to two times. Some producers have piles that are too big to turn and should educate retail yards on the importance of turning.
- Give colored mulch more time to cure when it's cold out. It can take weeks to cure in the cold.
- Educate customers to avoid complaints. Most wash-off complaints occur when it rains soon after colored mulch is applied. Landscapers and homeowners need to be aware that they should lay down colored mulch when the weather forecast shows dry conditions for the next day or two, so the colored mulch has time to cure.
Important drying tips:
- Don't rush it. Bagging, shipping and applying mulch before the colorant has had ample time to dry properly can result in premature wash-off.
- Save on shipping. Allowing colored mulch to dry thoroughly yields an end product that weighs less — reducing shipping costs.