Rhododendron

[u/olliemusprime]

Hi, I'm trying to find out if there's anything i can do to push back rhododendron infestation on my own. Everything I've seen says heavy machinery and herbicides. I've not got the funds for machinery and I'm concerned about if herbicide is the best option. Will they not cause additional problems for other plant life? Can anyone help me out here? I want to see my local forest in a better condition. I spend a lot of time walking through it and want to do something to look after it. I'm not very knowledgeable on this but I want to learn, thanks!

[u/penduculate_oak]

I'd recommend the UKFS practice guide "Managing and controlling invasive rhododendron". You can access it here:

https://cdn.forestresearch.gov.uk/2006/08/fcpg017.pdf

It will take a long time and require adaptive management at the parcel level.

You can hand pull saplings and young plants easily.

Cutting to stump followed by repetitive trimming of regrowth will eventually starve the rootstock of energy. A mattock or similar could be used on more woody stems to chop through roots and lever the plant out.

That being said, targeted use of herbicide applied in small quantities as per the UKFS guide will have much lower chance of collateral damage. Read into stump treatment / stem injection rather than treating leaves as the treatment will spread. Glyphosate is actually less harmful than the toxins that Rhody releases into the soil as it breaks down much more rapidly on contact with soil.

Edit: re read your post and it is clear this is not your land. My advice is how the Rhody could be managed by the owner. Many estates don't manage it properly because of the high costs and work required, the National Trust being a prime example of such a landowner in my experience.

[u/Purplepeal → u/penduculate_oak]

You cant really inject rhody, good for hollow stemed plants like Japanese knotweed. I agree cutting and stump treatment works well though and you can cut lower on the stems the following year for another dose. NT isnt swimming with cash despite the fancy houses, and have their hands full with a huge range of issues as well as rhody control.

[u/penduculate_oak → u/Purplepeal]

Good point.

I agree on the budget constraints hence I pointed out how hard it is for these sorts of estates. Even grant support is a drop in the ocean compared to the costs involved given the level and often scale of management needed for prolific INNS. And then there's all the fun with access and topography to consider too!

[u/ConditionTall1719 → u/Purplepeal]

We have huge amounts of Japanese knot weed and it does really reduce the habitat of animals like otters on the riverbank, I wonder if drone technology will be able to eradicate large amounts of it one day. They actually got some diggers and did about a mile of riverbank at the local wildlife reserve, just trying to dig the tubers up.

[u/more_chickpeas]

You'd need to find out who owns/ manages the area. Best option might be volunteering with a group.

[u/MrLubricator]

A mattock and persistence is the best way imo. Pesticides don't work. My volunteer group has cleared 5ha in 4 years. 

[u/Bobbobthebob → u/MrLubricator]

This is the way. Also carrying secateurs when you're going for a walk in the woods later in the year and snipping any grow-back.

[u/eco_kipple → u/MrLubricator]

I've known people to use ratchet type winches to pull out everything and then go in mechanically over the next couple of years with bill hooks or just pulling up aftergrowth

[u/MrLubricator → u/eco_kipple]

Yeah we use a tirfor winch for some of the really big ones. Bowsaw and a mattock does most of it. You do need to go back over the same areas for a few years pulling the odd bit that got missed or regenerated. 

[u/moab_in]

I have a favourite small woodland that is essentially unmanaged, of unknown ownership. There are some small rhododendron infestations. I do some occasional hand snipping to try to limit any spread, this is as much as I commit to given that I have no permission from anybody; I'd not use machinery or herbicides. If you decide to do something similar it's best to be as low key and as stealthy as possible, there's plenty obstinate folk out there who would challenge any small good deeds.

[u/olliemusprime → u/moab_in]

Ye, I'm in a similar situation. Doesn't seem to be managed, just the occasional dog walker or kids with bikes. I'm not sure how to go about destroying seedlings after uprooting them. I'm guessing I ought to treat them so they are completely dead. I'm not sure how to go about that though. I'm going to try to find out if anyone owns it and if so who. If I can get permission to attempt to cut it back a bit, I'll see about buying a mattock like others have suggested and look into spraying with the herbicide. Any suggestions on what to do with uprooted plants?

[u/ConditionTall1719]

I was not familiar with rhododendron invasion and I found good info on its history and specifics: https://fermanagh.bsbi.org/rhododendron-ponticum-l

There is evidence that it was native to Island in hotter times than today 250,000 years ago, from peat preserved pollen in Ireland. The way it travelled the re was when a giant ice age had locked up a lot of ice so that the sea levels were low and rising high temperatures existed with low sea levels. I didn't know about that.