Herbicide to kill orchids?

[estación seca]

Does anybody know of a good herbicide for invasive orchids? Years ago Dow made a product called Dowpon that supposedly killed monocots but left dicots unharmed. It was sold to kill grass invading flower beds and crop fields. I haven't seen it for a while, so I don't know whether something like that is still manufactured and sold.

I'm asking because in late fall 2013 I planted a Thelymitra azurea in a wash that runs through my property. This is a winter-growing, summer-dormant plant, and I already grow a lot of bulbs like that. They do really well during our cool winter with occasional frost, and I hoped the Thelymitra would likewise do well. During the winter this area is frequently damp. The plant did really well, growing and blooming in early 2014, and it set seed. Unfortunately, before I could harvest the pod, it split, and the seed blew away.

Well, the following fall 2014, among the grass that normally sprouts there, I saw something new. I'm supposed to remove the winter annual grass from the wash per the homeowner's association, but I thought I might have Thelymitra seedlings. So, I hand-weeded the grass and let the plants grow. Indeed, they are Thelymitra. But they didn't bloom in early 2015; I guess they weren't mature enough. I kept talking to neighbors about wanting to keep them, and nobody filed a complaint.

Last fall, 2015, they again sprouted. There is now a large patch of them, in flower. I think they look really nice. But, somebody has filed a complaint at the homeowner's association, because I am allowing unsightly weeds to grow on my property. I have 2 weeks to remove them.

I've tried hand-weeding, but the soil is very rocky, so that is extremely time-consuming. That is why I'm asking about herbicides that will kill orchids. I'd like something that will kill all of them but not harm the nearby desert trees. Anybody have suggestions?

Thanks.

[Fernando]

Hand-weeding is the best - do it quick, just works this special day. It's a really annoying blue pest.

[Subrosa]

Thelymitra as a weed.........

[estación seca]

Be careful what you wish for.

[Subrosa]

Originally Posted by estación seca

Be careful what you wish for.

Well I'm throwing caution to the winds. I wish I had Thelymitra as weeds!

[Orchid Whisperer]

Roundup should do the trick. If the growth is mature, you might want to use a weedeater to chop foliage down first, then hit the new growth with roundup as it re-emerges.

[estación seca]

I would worry the Roundup wouldn't kill the underground bulbs, and I know the soil microflora is very important in desert areas, so I don't like spraying Roundup. It can kill soil microflora.

We have a big problem here with nutsedge, a type of dwarf papyrus that sends roots down multiple meters to form tubers, which may survive in dry soil over 15 years. There are specific chemical for applying to the leaves that kill the tubers as well. I wonder if these would work on orchids?

[soobie]

I hate homeowners associations. I lived with one once that wouldn't let me have a clothesline. And don't even get me started in the internal politics and egos.

[AnonYMouse]

It's a weed if grown directly in the ground. It's horticulture if planted in a pot.

[AndreaK]

I hate homeowners associations also. We had to move to a location nearer my husband's work. We have 3 to 5 acre lots, but I hate having naggy neighbors. So far it has not been too bad, but I look forward to moving soon. I want more property away from neighbors and definitely away from HOAs. We have many renovations to complete before we can make the move though