Might want to dig them up and put a healthy dose of manure and/or compost then re-plant, because all the nutirents will flow through and you want to deter nurients from flowing through. also a handful of bone meal wouldn't hurt. Although I don't like peat moss that might help as well, because the wind will dry the moisture faster.

Here is a link that might be useful: Propagating Perennials

mine do just fine in pure yellow sand ... no fert.. no amendments ... a little water to get new plants going the first year.. and you cant beat them back with a stick ...

a quick google trip for zone info.. lists most as zones 4 to 8 ... with a sporadic 9 ...

do you have the appropriate forsythia for your zone??? if you bought locally.. one would hope you do .. but if you mail ordered in the wrong plant.. nothing you do might help ...

do you see any others in the neighborhood ... since they root so easily .. you might beg some local cuttings.. and root the plant that you know will grow in your area ....

ken

Thank you, bullthistle and ken. I am going to go ahead w/ the topdressing of manure and mulch. Their hold on life is too tenuous to want to dig them up. They were bought locally. And I do see large, abundant forsythias around here. Maybe the fact that mine are on a slope, (not a steep one, but still a slope), has something to do w/ it- water draining away, the wind? I will hope that the manure will fertilize them over time and the mulch will help hold in moisture. I know when I lived in a place w/ more clay type soil that they were actually hard to kill- chopped them down and they kept coming back. Maybe they didn't get enough water in their first yr when they were getting established, too. Thank you both. Brandy

Amending of planting hole backfill is not beneficial unless you amend the entire bed so that the entire potential rooting area of the plant is modified - as can easily be done with small plants like perennials. Many kinds of these are also apt to be dug up and divided at some point, at which time the bed can be re-amended. Shrubs, on the other hand, are nearly always going to have to live for decades with the original planting method being the only thing affecting the site conditions - other than maintenance operations including mulching. Organic amendments incorporated at time of planting will decompose and disappear long before the shrub is no longer being grown on the site. In one instance peat dug into a soil in Oklahoma was seen to have vanished after one year.

Amending of planting hole backfill has actually been found to be detrimental in many instances, due to how movement of water into and out of the amended planting hole is affected. If a significantly different texture from the soil outside the planting hole is created within the hole by amending - much of the point of amending - then the backfill with have a different attraction for water than the soil around the hole. On heavy soils during wet conditions the amended planting hole make even act as a sump, subjecting the new plant to drowning and rotting of its roots. During dry conditions the less coarse, unamended soil around the hole may have a greater attraction for water, resulting in chronic drought stress to the new plant - unless and until it roots into the unamended soil outside the hole.

Undisturbed potting soil rootballs are subject to the same factors, even when planted in unamended backfill. This has resulted in recent recommendations to bare-root at planting time. Exposing the roots also makes inspecting them for deformities possible, kinking, j-rooting and circling are very common among plants produced in containers.

i think the problem is lack of water.. ergo lack of 'establishment' ..

no fertilizer .. nor amendment is ever going to help that situation ... and will be a complete waste of money and effort if you do not do what is suggested in the next paragraph ...

add a course mulch to about 3 inches.. in a 4 foot circle around the base of the plant .. and insure that the soil never completely dries out for this summer [insert finger to second knuckle and water when it starts to warm .. damp soil is cool with mulch] ... next year... let them dry between waterings ... free range thereafter ...

IMHO...

you were right .. IT IS THE SAND ... but you are wrong to think its nutrients [or lack thereof]... it is the sands inability to hold water .. and keep the roots cool ...

ken

Yes, bboy, I'm aware there are opposing viewpts re soil amendment. I consider it sufficient to put in some well-rotted manure and then some mulch to help hold water. The plants may have been potbound (most local buys are from box stores) but I would have spread the roots out and cut if necessary. I will keep in mind the suggestion to bare the roots when planting container grown plants.
Ken, I am inclined to think the major problem is lack of water. So, I will increase the circumference of the mulch around the shrubs on that slope- there are also burning bush and weigelia, there. Maybe I will plant a cover crop of rye grass come fall- one way of improving the soil.
Thank you both for your assistance. Brandy

Since it began to be seen about 40 years ago that plants in amended planting holes grew less than their counterparts in unamended holes on the same sites I think we are pretty much past the opposing viewpoints stage. If you look at subsequent studies results are pretty cut and dried, except where misinterpreted or mishandled - the lingering of opposing viewpoints being due to the tenacity of tradition rather than a strong dose of countering facts.

And funding for researching such questions has pretty much dried up for some years now, stalling further progress.

It maybe that I am from the old school when it comes to global warming and imports, because society demands cheap, but I planted plants that did not do well and redug them and their roots were in the same ball as planted so I amended the soil, here in NC Piedmont it is clay, and they did well thereafter and when I did design/build in CO I never lost one plant, but when I go into HD and people are returning dead plants, never grown out of their root ball, it tells me there is a right way and a wrong way. Some people are always trying to change things with scare tactics and there are those who will listen and there will those who ignore. Now if only the experts will solve the honey bee problem all of society will be better off.

Here is a link that might be useful: Propagating Perennials

If you're actually interested in finding out what has been done and why certain conclusions have been reached, look for the publications of this guy. Libraries of colleges with horticulture programs here where I live have them, perhaps where you are also.

Here is a link that might be useful: Lacebark Inc. Books

one would be better off... planting at the appropriate time of the year ... and bare rooting the plant [removing all the potting medium] .. rather than amending to soil ... putting aside the arguments over clay.. in which i have no experience ...

potting medium is 'engineered' to work in pots ... there are so many variables ...

the problem with sand.. and i know from the experience of moving 1500 potted hosta from one house to another... is that the sand will leach all the water out of a peat based potting medium as the summer goes by .... during the heat of the summer.. the peat eventually dries out .. and no amount of water.. will rehydrate it.. and in the case of hosta.. that means the plant dies from root rot ... the plants i popped out of the pots.. and planted.. many died .. the ones i bare rooted out of the pots.. thrived ... with enough water ...

and then we are back to the issue of sand and water ....

anyway ... how did you plant them in the hillside???

on my sand when i do such .. i dig out the backside of the hole.. so that i can lay down a couple gallons of water .. so it has time to soak in .. before it runs down the hill ... in essence.. i build a moat ....

you can probably still do such ... as the increased water.. will surely help the plant prosper.. more than the thought of some minuscule harm to roots .. if you get the water to the root zone ... the plant will be much further ahead

ken

My whole lot is sloped, except the lower wooded portions where water sits :) It's a difference of about 10 ft from top to bottom. The shrub border is not a priority so it gets less water than the bulb garden and rose garden and tomatoes.
I will let you experts argue over the question of amending or not. The mulch is to help hold water so the moisture doesn't all seep away into the sand. Other plants in the sand have done well- especially the cleyera but they have some shade where they are, of course, they get watered even less than the forsythia. I am going to go w/ the moat idea for now. (By the way, I have ligustrum there also and it has done much better.) Probably just my mistake in buying from a certain box store. Brandy

I agree the likely problem is they need more irrigation. Your area was/is likely experiencing drought. On a slope, and being a plant that was not given priority watering, it probably didn't grow so lush. I do the same thing. I just do not water, unless absolutely necessary, and I try to plant things that will do without extra watering. So I agree mulch is the best thing. Also I would not recommend commercial fertilizing, other than top dressing with compost. Forsythia are tough Southern passalong plants and many thrive for years without care. I have another suggestion: after they flower, as mine are doing now in north MS, prune them somewhat to stimulate new growth, and do the compost when they start actively growing. I hope that helps. I am starting to hear more about bare root planting and I think I will try that more. In Louisiana, it was easy to grow just about anything in our Mississippi Delta soil, which was more sandy. Here in north MS it is clay which is more of a challenge to me.