Black landscape fabric & effect on going into & out of dormancy

Coming up… The random thoughts of the restless mind syndrome (better that restless leg syndrome, I hope)

I am thinking of covering a large area in my orchard with black landscape fabric to fight weeds.

The goal is to keep weeds down without resorting to pre and post emergent herbicides.

This will be the heavy duty fabric and will NOT be covered with mulch so as to avoid creating a rooting environment for weeds. Being uncovered will make it a much more hostile environment for weed seed germination and make it easier to deal with any that might.

I understand that the black fabric will change the micro environment.

THE ISSUES RAISED IN MY HEAD:

In the fall…

  1. Will it delay the trees going into dormancy in the fall because of the warmer micro-climate created? . The upside effect is that it may give the extra time for some late ripening apples like Goldrush and Pink Lady to do so more regularly in zone 5b . The downside is whether it will delay dormancy so that the trees don’t harden off in time for winter?

In the spring…

  1. Will the black fabric warm up the soil too soon in the spring so as to bring the trees out of dormancy too early and raise the danger of spring freeze damage?
  2. What would be the effect on the timing of the emergence of insectoid pests?

Any thought and/or other issues that I did not think off.?

Just stirring the mental pot a little… got to keep the juices flowing so the grey matter doesn’t atrophy :cold_sweat:

Thanx

Mike

Mike:

I’m probably one of few here that’s used black fabric around trees for yrs. I’ve had the same questions and maybe a few results. But our climates are very different. Here the issue is insufficient chilling, excessive warmth winter and spring, and late freezes. I think this yr the fabric delayed bloom despite increased spring warmth because it reduced chilling. As a result my apricots bloomed 10 days later than my buddies and set better. In another yr or climate results will be different.

In NY with more clouds my thoughts would be that the fabric won’t have any large effect fall or spring most yrs. You won’t lack chilling and I don’t think dormancy will be delayed more than a couple days. Also don’t think it will lengthen your season as regards apple ripening by any more than the same amount. Your trees given excess chilling all yrs might bloom a few days earlier due to extra spring warmth. But the fabric might also affect temperature during spring freezes by 1-2F.

The fabric will also provide more water to your trees. Not always a good thing. But probably no more than wood chip mulch. I had a peach this yr grow 8ft on the black fabric with no applied water. We’ve had a wet yr but only about 12-15 inches total since Nov last yr.

I use commercial grade black plastic in my watermelon patch and in my rose garden, strictly for weed control
as you are wanting to do. In the spring, it does heat up the soil, which aids in seed germination, but does little for water retention during the growing season. Once the canopy develops, the heat advantage is eliminated. As far as the roses, the plastic provides no real benefit beyond weed control. If your sole reason is weed elimination, why not heavily mulch the trees with 5-6 ft ring of mulch, and then apply the plastic between the trees. In that way, the trees will receive the nutritional benefit of the decaying mulch, which they won’t receive with black plastic. The mulch will also help to retain water, thereby reducing your watering needs, and will greatly retard weed formation. It’s kind of like having your cake and eating it too. You eliminate the weeds between the trees, while basically achieving the same weed control at the base of your trees, and helping to feed and water them at the same. I doubt that all black plastic will have any real effect in your areas of concern, especially in your climate.

I lay down cardboard (free) and woodchips over the top…usually buys me the summer. Next year same thing…excellent soil being made int he process…lots of wormies.

@warmwxrules

That is what I did for the last four seasons/years. I mulched the entire orchard floor (150 x 50 feet) heavily with shredded smallish trees, branches etc because of the pretty heavy clay concentration not to far deep. I basically built one foot deep by three foot wide raised berms and planted the trees 50/50 in the raised berms and the original soil .

After four years much of the mulch has broken down and created a great loamy layer that the trees love. But also, created a great weed nursery.

@rayrose,

My trees are espaliers on a narrow berm so the roots spread along the berm in the same shape as the tree not out in a circle. Next season, I plan to lay down a 4-5 inch layer of true hardwood chips (not shredded) that will take much longer to break down and will keep weeds out and still provide long term soil improvement. But, at $25.00 a yard… /&#@*! I am going to use the chips only on the berms and the black cloth in the aisles and the outer perimeter.

@fruitnut

Your greenhouse gave me the idea to do the cloth WITHOUT a mulch layer above.

Mike

Make sure you use a black landscape fabric that’s meant to be installed directly in sunlight. I use DeWitt Sunbelt which has UV stabilizers in it.