[Branleur]

I have a 40 m. hawthorn hedge whic :-\h I guess must be around 80 years old but due to the proximity of ash trees the seeds have infiltrated the hedge and now its a complete jumble, with the hawthorn being overwhelmed by alien plants.  How can |I renovate this hedge or must I grub the whole thing out and restart?  Can one actually buy hawthorn plants, or could I take cuttings and try to renovate it that way?

[Backinwellies]

Old hedges are amost always mixed species ...... natural biodiversity.   For stock proofing maybe it  could it be laid?
Linda

[Fleecewife]

The mixed species hedges started off as just hawthorn when the fields were enclosed - whenever that was ?250 years ago?.   Over the years they have gradually grown more varied and now you can estimate the age of a hedge by the number of species in it.   Hedges even older than that are still to be found and show that an old hedge is not a bad hedge 
 
Yes you can buy hawthorn plants (try Buckingham Nurseries  www.hedging.co.uk)
 
However, as Linda has said, you can restore an old hedge by laying it.  Advice is available on how to do this, and even help.  It would be such a shame to rip it out just because it's messy.  Hedges take ages to regrow and become established.  You may even find some U-tube clips on hedge laying - it's quirte a skill but one well worth learning     

[Sylvia]

If you root out your hedge you will have to wait for about 100 years to get it back! Just keep it well cut, the ash will "bonsai" over the years.

[Barcud]

If the hedge is old and tall you'll find the hawthorn difficult to lay as they will be rather brittle and top heavy. Probably best to coppice the hawthorn back and let it re-sprout, then lay it in 8-10 years time. Don't grub it up. Planting up gaps in an exisitng hedge is a bit hit and miss as the exisitng root systems will outcompete the young plants. You'll need to get plenty of organic matter in and around the roots. If you can by plants of local provenance - plants raised form seeds collected in your part of the world, as they will be better suited to the prevailing conditions. To increase the biodiversity value of the hedge consider gapping up with species like hazel and balckthorn, with the odd holly, field maple, guelder rose and buckthorn.