To give some context, the tree in question is a 1 year old “Stark SweetHeart” apricot grafted to what I believe is a peach redleaf rootstock, it was planted early spring and has been doing quite well up until recently. This is the third one I’ve planted because the previous two all failed to thrive and were replaced by StarkBros - second one got lost by Fedex and arrived kind of sickly looking, did okay after planting but died two months later.
Anyway, I first noticed yesterday that it was the only tree showing some wilting in the middle of the day which I though was odd since it rained the day before. So I checked the soil at the base and it seemed damp but then I found that there appeared to be some sap coming out of the graft union area… a LOT of sap. So much so that it had saturated the soil in a 1" diameter area around the base turning it into a gummy, paste-like consistency. I checked my video logs and the tree was doing okay a week ago and has survived the >90°F heat wave we had that made all grass go dormant in my area the week prior, which makes me thing its either a recent issue or it’s finally getting serious.
I cleared the area around the base of the tree and made a video of the graft union and sap. Reviewing the footage I can see a little root that seems to be coming from above the rootstock which makes me think that the mulch may have shifted and piled up around the base enough that the grafted apricot tried to root on its own. Not sure what to do at this point or if there is anything that can be done to enhance its chance of survival.
Update: Here it is a few hours later with the soil dry and the sap clearly shown. There’s also a greater loss of rigidity in the leaves compared to yesterday making me think its rapidly getting worse.
It could be a delayed graft incompatibility, or there could be a canker infection at the base. In either case there is not much you can do unfortunately, either it recovers or it doesn’t. Make sure the soil is not too wet and not too dry.
Would shading it and misting it with water help at all?
Shading it could help a bit. Misting only lasts for a few minutes so it probably won’t do anything. If its a graft incompatibility there is really nothing you can do, it will eventually fail.
I see. So the delayed graft incompatibility, could it have been caused entirely by the grafted tree trying to root into the mulch?
Because I feel like this is the same exact thing that happened with the last two apricot trees I got from StarkBros, but it can’t be that I’m an idiot at planting trees when all six of the other trees from them are doing great. Not sure if I should even bother asking for a refund or buying another apricot tree from them…
I can’t see how scion rooting would cause a graft to fail. If a scion roots its just widening the stream, there is no reason it would shut down the main root. But it could be the other way around, it is rooting because the graft is not giving the scion good sap flow.
Could you possibly save it, if the issue is graft incompatibility, by putting soil around the graft area and hoping the scion part roots out?
(It seems like it might work conceptually, but I don’t have the experience to know if it would work out in reality.)
That graft union does not look very good. Might be delayed graft incompatibility or canker, as @scottfsmith said, and you cannot really do anything about these. Another possibility is that borers attacked the peach understock. In that case, there would be entry holes near or just under the ground level.
Thats a good suggestion on borers Stan – I forgot its a peach root. To see if its borers look for sawdust in the sap, that is the easiest way to tell.
I think it might work if the new root system of the scion can grow fast enough. The problem would be that the tree would lose all the beneficial characteristics of the rootstock.
@scottfsmith @Stan I am definitely leaning towards your peach tree borers diagnosis. Most of the fresh sap seems to be coming from two points just below the graft union, in the peach rootstock. I took a 1mm copper wire and poked into where the source of the sap appeared to be, it definitely seemed “hole-like”. Will keep an eye on new sap.
But the real reason why I think its peach tree borers is because I just checked my peach tree that’s right next to the apricot and it had 6-8 nodules of sap along the trunk and main scaffolding.
There is no benefit for apricot to be on peach roots, it’s just easy and cheap to make for growers.
Any suggestions for an alternative to StarkBros? I like buying from them because they sell 3 ft / 1” caliper trees.
Young trees grow very fast, if a smaller tree is healthy it will catch up to a larger one in no time. There are many nurseries listed in the Reference section: http://www.growingfruit.org/t/nurseries-list/7060. Except for a few rare varieties I buy from Arboreum, I mostly graft my trees myself.
I purchased my apricot trees from Bob Purvis, Adams Co. Nursery, and Bay Laurel. All growing great. I like the Purvis tree’s understock the best, though. It’s on Manchurian which thus far seems to have far fewer problems than the peach and plum rootstocks most places put apricots on.
Young trees grow very fast, if a smaller tree is healthy it will catch up to a larger one in no time.
Makes sense. The only difference between a bare root large and small tree is the amount of energy stored in the wood. On top of that if people chop their tree down to knee high at planting it doesn’t make any sense to get a larger tree.