Thickening Hawthorn

[jameson_uk]

We have a Hawthorn bush that is really thick and healthy up top but there isn't much in the bottom half. You lot seem to be knowledgeable so looking for advice on whether there is anything I Can do to thicken it up at the bottom.

This had been left by the previous occupants and I think I have taken a good 1-1.5m off the top over the last few years but I have never managed to get much growth near the bottom.
This gaps had been filled by this

which I am guessing is a weed and probably hasn't helped the Hawthorn but ripping out loads of this has made the hedge look a little bare.

Do I just let whatever that is fill the gaps (it grows incredibly quickly), plant something at the bottom and hope it will go in the shade or do I need to take more serious action and trim things right back to stimulate some growth?

 

[mort]

It quite a common problem because you get more growth on the higher parts of the plant. Hawthorn wants to be a shrubby tree and therefore it sends its nutrients to the top where it gets most light. This means we need to really trim it back to the base to get any real growth at the bottom. So you could reduce it to the top of the bare bits, where it will regrow and then can be maintained as a hedge again but it will take a few years.
The other way to do it, is by layering some of the longer bottom shoots. You can essentially bend them down to fill in the gaps. There are guides how to do it but if you can leave some of the lower grow a bit longer when you trim the rest, it will give you material to fill in later. Ideally leave the bottom of the hedge slightly wider than the top as it let's more light reach the base and keeps it healthier.
Try feeding it in the spring and perhaps mulch it this autumn, which might help with some growth.

I'm not sure what that plant is that fills in but you could use other plants to fill the gaps for a quick fix, or if you want to try and get the hedge back, clear around the base to maximise light and air. If you have competition around it, you'll likely not get any real growth there.

 

[jameson_uk]

I'm not sure what that plant is that fills in but you could use other plants to fill the gaps for a quick fix, or if you want to try and get the hedge back, clear around the base to maximise light and air. If you have competition around it, you'll likely not get any real growth there.

Given where it is I am keen to avoid cutting it right back but I suspect that is the only option to have it back as a proper hedge. I had already tied a couple of stragglers into the gaps but I am not sure that was the right thing to do as I am bending new growth back into the shade. The other side is a footpath so I can't really let it grow out too far on that side but I will keep bending shoot back around. I did wonder whether new plants would actually grow in the shade or whether they would just die off due to lack of light and the well established plants taking all the nutrients.

Some other pics of the stuff that keeps growing (it is about 6' after six months)

 

[Tyko_N]

The other plant looks a bit like Symphoricarpos albus (snowberry) which might be possible to trim into filling the gaps.

 

[foxfish]

Hawthorn will readily bud from the base you just need to encourage it to do so.
Morts advice is sound.
Thin out the top section with secateurs, cut out every other branch and cut back the length of individual branches to make each one stand out as a single item.
Best done in February March time, if I lived anywhere near you I would do for you as I love trimming trees and shrubs, not sure why ! !

 

[PARAGUAY]

Not being so knowledgeable on it if you wanted to keep at its height now, how about a mini hedge in front slightĺy . Seen plenty of tiny hedges something similar to box possibly.

 

[tam]

Rather than cutting a very neat vertical face, slightly slopping it in towards the top may help as that allows more light to the lower sides. Have you fed it? Any time you want more growth a good feed will help.

 

[mort]

With the extra pictures I agree with tyko_n it's snowberry. It's a good woodland species so goes well with the hawthorn. The simplest thing would be to just let it grow and fill the gaps as it can be trimmed into a low hedge. If you want to give the hawthorn the best chance of recovery then you need to keep the area open. I don't think adding new hawthorn plants at the base will help as they will be out competed by the original hedge unless you really look after them. Bending growth down should be ok even if they are in shade. This growth might not thrive but it's a woodland plant and can do well in quite dark conditions. The lower growth will never be as vigorous as the upper growth.
I'd try a good mulch and feed to see if that improves things but I'd also probably just add some more planting, a metre or so away from the hedge, that will grow up and block your view of the hole until it recovers a little.