Forsythia buds are formed over the course of the summer on the new growth. So if you prune it in late summer or fall you will be cutting off the dormant buds. The time to prune it is immediately after it blooms in the spring. This allows time for new branches and buds to form for blooming the next spring. With an old overgrown bush you should not be afraid to give it a very severe pruning or even take a chainsaw to it. In your case I would probably cut the whole bush back to about 16 inches from the ground right after it finishes blooming. Then just stand back and let it grow back naturally over the course of the summer. If it gets regular water it will easily put out lots of 3-4 foot new branches in one season all of which will bloom the next spring.

or just link to steves other post ... see below ...

SHRUBS are defined as a group .. one key to the group is how you prune them.. among other things ...

rejuvenation pruning involves removing up to 1/3 of the plant per year .... the biggest 1/3 of the branches.. as close to the ground as possible ...

google 'PRUNING SHRUBS' .... and you ought to get a couple million links ...

trees and conifers are NOT shrubs.. and have much different pruning requirements ... so dont go trying to prune a conifer in this manner .. and conifers are not evergreens either ... my point.. words mean things .. once you start learning the terms... there is a world of knowledge awaiting ....

good luck

ken

Here is a link that might be useful: link

>> rejuvenation pruning involves removing up to 1/3
>> of the plant per year .... the biggest 1/3 of the
>> branches.. as close to the ground as possible ...

I agree that Ken's advice is a less traumatic way to prune a shrub and it keeps the shrub looking better while it is undergoing the pruning process. As Ken mentions forsythia is an unusually rugged plant and it can endure extreme pruning like shearing it right to the ground but you definitely should not assume that this is a useful technique for all shrubs.

thank you everyone for all your suggestions. the thought of cutting it all back to the ground makes me sad :o( it's a pretty good size bush (maybe 4' x4'), but i just have to keep in mind it's good for the bush and it will be healthier for it. thanks again

sad..??

you are a newbie.. we will guide you ...

i have seen them at least 10 x 10 .. and maybe 15 x 15 feet ...

will it make you sad to trim back a shrub that is eating your entire back yard????

you trim your hair.. well.. most of us do.. does it make you sad ... most likely not ...

so why should it make any difference with a shrub ...

properly done.. the plant heals itself.. and is no worse off with a good haircut ...

they are your plants.. not your babies... show them who is in charge.. treat them like the inert object they are ... and they will be fine ...

proper pruning is a blessing to a plant.. not a negative...

boy.. a metaphysical forsythia debate .. go figure on that .. lol ... i cant wait for the weather to change.. so i can go out in the yard and turn off this machine .... might even go find some shrubs to teach a lesson too ... lol ..

good luck

ken

You are crackin me up Ken LOL and you are right about me not caring about cutting down an annoying growing vine that i don't want growing! Ok i'd like to get clarification to make sure i do this right. First I wait til after it blooms, which it's doing right now, so i'm guessing sometime in April would be a good pruning time?? Then do i cut it back all the way to the ground or should i leave it a certain height? This harsh pruning do i do this every spring, every few years, or only if the bush shows signs of looking unhealthy? Thanks again for all your help!

only wait.. if you want to enjoy the flowers.. if you dont care.. do it now ...

get a pruning saw [see below and link] ...... pick the thickest branch ... and cut it out as close to the ground as you can get ... within about 6 inches.. sometimes you cant get all that close ...

when that one is out.. pick the next biggest ..

keep going until you are happy ... on this plant.. you can go all the way if you wish .. it will be back to half size by fall ... i will bet a buck ... not true for all ... mind you

thank god you cracked up.. i was worried i was offending you

the saw at the link is a great investment.. if you have many shrubs to take care over the years ... it folds for safety .... and will cut through a 2 inch branch in about 3 swipes .... i have seen generic knockoffs for as little as $10 ... i just linked to a picture ... though amleo does have fine service ...

i had a horrible forsythia .. decide it was a goner... cut it to a stump about one foot off the ground.. and applied 100% roundup ... and it resprouted .. so i trimmed back the sprouts and again dripped 100% on it .. and i think i had to spray it one more time with diluted stuff ... you really arent going to hurt this thing with a little pruning.. trust me ...

any branch you find that has touched the soil.. and rooted in.. can be transplanted for a new plant.. if you wish ....
gotta run ...

ken

PS: the process is called rejuvenation pruning .. and works for ALMOST all flowering shrubs .. but check with us before you think about doing it to other shrubs ... lilac is the same ... mock orange.. quince ... olive bushes .... spirea... oh the list goes on .... ad nauseum ....

Here is a link that might be useful: folding pruning saw

Thanks again Ken for all the information that i so deparately needed LOL

I'm excited I got 5 new flowering shrubs for my birthday that i can't wait to plant. I got 2 knockout rose bushes, 1 red 1 pink, a lilac bush, an althea (rose of sharon), and an azalea! If you have any suggestions on how to plant any of those that would be awesome. Otherwise i was told by the nursery to plant them level with the ground and not dig too deep, they said people have a tendency to do that. The nursery also said to add some compost/manure in the hole before putting the shrub in. I love spring and summer, can't wait to watch all my pretty plants/flowers/shrubs grow. Happy Growing Everybody!! :o)

I can't remember something my grandmother used to say to me - it had something to do with "once the forsythia bloom........" and i can't remember the rest. Does anyone know what I'm talking about?

Great post! This is just what I needed. I moved into my house in 2008 and I have overgrown shrubs and trees EVERYWHERE! This year I think I'm ready to tackle my giant forsythia. It's got to be at least 6' high by 10' long by 4' deep. It's too giant for me to selective prune without shoving half my body in it. I think that means it's time to hard prune. Thanks!

@pjt108. I had been taught that when the forsythia in your area bloom it is time to give your roses their first meal of the season - 1/4 cup Epsom Salts spread around the base and then watered well in. I did that for many years and had enviable blooms.

PS Recently, I had to leave behind my 44 rose bushes because we moved fro the city to a rural home with deer as neighbors. I had been advised deer eat roses thorns and all. Since they shun forsythia, I am researching which variety to get for zone 6b.

Deer like forsythia around here, but there are many shrubs deer find unappealing, among them Abelias, Deutzias, Clethras, Ninebarks, Spireas. This is by no means a complete list.

@laceyvail - thanks!