Just moved onto new property, it has a good? dam but there are numerous small trees growing on the walls, mostly seedlings up to 2-3 metres tall but quite spindly. I have been told by a couple of people to cut these trees down as they will eventually damage the structure. Lots of scribbly gums in the paddock (acid sulphate soil area) so I wouldn't be denuding the area. Any knowledgable advice would be welcome. Silkhay
I did replybefore but it hasn't appeared? The trees are on the raised wall & the edges - the bits that hold the water in!!
keep the dam wall clear of all except maybe woody weeds for habitat. when a tree dies or whatever then the roots rot out generally the dam wall gets broached. have seen dam wall in this collapsed state. i would keeping 6 to 10 meter clear around the wall. the water in the dam would be a great attractant to tree roots. len
Water can also travel along roots in-situ. Digging emergency drainage during the floods, came across a 20mm root which I cut, water began to flow from around it like a garden hose.
Is it better to leave the stumps then? Given that most of the trees have a fairly small circumference, should we paint the stumps to stop them reshooting. What is the pink 'stuff' you see painted on stumps? Also what would be a suitable clumping grass, something like 'lomandra' to cover the area. It is in Zone 5 at the boundary of the property.
Pink stuff would be paint, usually (some poison can be dyed). It's for visibility. Since you are going permie, you aren't poisoning. Either smash it down to the root plate with a mattock edge, or cut it low and just remove any epicormic growth until they exhaust stored carbohydrates (longish process but creating mulch material). Lomandra, Carex, Juncus, Gahnia, Dianella etc. if you are staying in Zone 5 . Many to choose from, just pick what's native if that's your Zone 5 plan.
Inoculate the cuts with some kind of fungus, like Paul Stamets' fungi-laced chainsaw oil? My only fear is that the tree roots may have already compromised the structure. Maybe not with such small trees, but don't take my word for it! Good thing you asked!
we let those woody native weeds grow up the side of the dam wall which is all but impossible to keep trim, dunno the names but one has squarish stem and blue paper like flower. these provide good habitat for the bush wrens etc.,. on the top wall think about wyncassia and lotonomus they have solid soil holding root systems. you will need some of the rushes and lilies growing at the waters edge to help clean the water, a good cover of water reed will keep cane toads from mating in the dam. we turned dam from muddy to clear with water plants and also those taller grasses spear, kangaroo types at the margin of the dam all helped keep it clean. len
Yes vetiver will certianly stabilize a dam wall. Take a look at: https://www.vetiver.org/g/slope_protection.htm
Another way to look at it... If it's a very long lived tree... it will be someone else's problem and you can just enjoy the trees and the shade they bring to your dam. I have sort of given up keeping my dam wall clear of trees. I think keeping live stock away from dams is more important.