I’m trying to help a friend who has a new multi-graft pear tree with the variety she prefers, Warren, that has no flower buds. At least two of the other varieties do have flowers. This tree is to replace a Warren tree that she had for several years on an unspecified dwarfing rootstock that never flowered. It did produce bourse buds, but negligible flowers and no fruit. I have had some experience in pruning various kind of fruit trees and doing some kinds of research on Bartlett pear, but I am stumped as to why neither of her Warrens has flowered. I helped her with pruning her first Warren tree as long as she had it and recommended fertilizer and disease management regimes. I read through some of the formum here and found that some folks have had to wait three to seven years for Warren to flower so possibly my friend is not alone in this problem. We are located in Davis, California, zone 9.
I see here and at Redwood Empire Chapter of the California Rare Fruit Growers that David Ulmer is the expert to appeal to for possible answers. I’m going to join CRFG and hope to bring my friend along too.
I’ve known of folks who waited 15+ years for their Warren to fruit. Some have given up and replaced theirs with something else long before they got that far out.
I have a Magness, grafted in 2001 that has never yet flowered. It’s a monster… probably 20+ ft tall.
I’m still waiting on my Warren to flower. I grafted it over and left one limb.
Warren pear is one of the slowest to produce varieties of pear there is, some people have managed to speed up it’s production if it’s kept in a pot, and if it’s grafted on to OHxF 87 root stock. In the ground I don’t think that there is a way to speed up it’s production.
Highly recommend not pruning warren it does not like it. Add Karls favorite scions to the same tree it might be a game changer. Magness and warren are loaded with blossoms again here. Its going to be a great year i think!
Warren are known throughout the industry as a hard pear to grow. Organic Warren Pears – Frog Hollow Farm
Voice of inexperience with Warren pears here. Indont know much about this variety, but a bit about plant physiology. We have been very successful at triggering reproduction in plants by focusing on trace mineral nutrition. Assuming the fundamentals of calcium, magnesium, sulfur, etc have been addressed, focus on providing generous levels of Mn, Zn, B, and Co (cobalt) before and during the bid initiation period for a strong bloom the following year.
I agree with you that fertilization is important. Warren likely produces well in Kansas because of our threatening climate. Trees produce under stress. My tree is grafted to callery and produced very quickly. Karls favorite being grafted to half the tree triggers hormones in the tree as well and provides pollen for the warren blooms.
Does Warren have the structure of Magness? My 3 Magness are on OHxF333 and they have great structure with branches coming off the leader at really nice 90 degree angles. If Warren has that structure as well it might not benefit from branch bending, but if it doesn’t, perhaps it would.
I planted 2 Orients and a Warren for pollination 5 years ago this spring. All bloomed last year & are heavily flowered this year. They are 4-5” diameter at the base 12’ tall trees after recent pruning. It’s been crazy warm this spring. I expect all to give me pears this year, if a late frost in 8A doesn’t happen.
Sounds like a good candidate for weighting or tying down limbs to horizontal, bark inversion graft or simple put it on quince or 333
Wow, that’s incredible. I have a couple of Warrens that are on their fourth leaf that are nowhere near that size – although (1) they were tiny when I got them, (2) one is in a location that loses an hour or so of morning sun, but nothing too drastic, and (3) the other is in a choice location but got heavily damaged by deer when they broke through my cage, so it got set back. They are tall and grow vigorously but are nowhere near as thick at the base as yours. I figure that I still have several more years at least before I see blossoms.
I’m not doubting you, but I’d love to see some pictures of your Warren if you have the time and the inclination.
Magness and warren are heavily budded up this year. Karls favorite should pollinate them both. Magness is a heavy producer once it starts but its going to make you wait just like warren does. Everyones climate is different.
This sort of topic can be confusing because some plants like fig trees produce heavy here each year nothing added to the soil, lots of things are low production here nothing added to the soil. I am guessing that some things are less needy of those things. Yet do they still benefit by having them. In European places that fig trees do best, there is a lot of calcium and magnesium in the soil naturally. Where we live is known for having low magnesium, and low calcium. Here is known for having no boron. Not sure about zinc.
FWIW, I bought Warren from Trees of Antiquity in 2017. It has bloomed consistently since then. It produced a few fruit starting in ~2020. I picked a decent crop last year 2023.
Did you keep it in a pot?
I don’t have a Warren pear. I do have 2 Asian pears that I started from seeds. Both gave me fruits in 5 or 6 years. I don’t prune them, until they are mature enough to give my fruits. Now, I been using their branches to graft onto other trees.
if this was directed to me, the answer is no. My Warren has always been in the ground.
Thanks for all the terrific replies. I’ll try to comprehensively respond to what everyone has said.
Not pruning isn’t an option. On the little multi-graft that was planted a year ago, Warren is by far the most vigorous scion of the four cultivars, with a caliper about double that of the other three and longer internodes, from the nursery (Dave Wilson, the predominant nursery for fruit trees in California). Therefore, in order to balance the vegetative vigor of Warren and enhance its reproductive vigor, we pruned it back about halfway which happened to be close to the smallest caliper laterals at the time of planting. All four scaffolds were then tied down to approximately 90° from vertical in order to enhance reproductive vigor and breaking of fruiting wood. The Warren tree that had been in the ground several years before removal had similarly been pruned and tied down for the same reasons.
Nitrogen has not been applied to either of these trees because it would preferentially stimulate vegetative vigor-- incidentally that would exacerbate the problem of fire blight which is definitely a concern here, both as blossom and shoot strikes. I’ve done research on targeted fertilization of Bartlett pear in California commercial production, and while we did not do any nutrient leaf analysis on these home-grown trees, they have not shown any signs of identifiable deficiencies and it’s pretty hard to induce stress under the current growing conditions such that we might expect to stimulate flower bud production, other than root pruning, which isn’t indicated in this case.
The multi-graft was not bare root but was pot-grown in nursery production yet never produced any fruit wood on the Warren graft while in the pot. Maintaining this tree in a pot would not be practical.
Regarding ‘hormone’ control of vegetative versus reproductive vigor in the Warren scion, I speculate that the plant growth regulator influence from the other scions is less likely than auxins moving basally from the Warren apical buds inhibiting flower bud production. This might be borne out in that the only bourse bud that formed last year on the Warren scaffold is closest to its origin and on the smallest caliper secondary.
Concentration of plant growth regulator can dictate degree of response, as in the example of auxin level inversely related to distance from the source. Tissue sensitivity to presence or absence, as well as concentration, of plant growth regulator is at least as important as concentration. It may be that vegetative apical buds of Warren produce more auxin than those of other cultivars, lower levels of auxin are required in Warren to produce fruiting wood, or the interaction of different plant growth regulators (probably auxin and gibberellin) in Warren influences its vegetative and reproductive vigor differently than in the other cultivars.
The fact that we have the same problem occurring in Warren both as a relatively mature single-scion tree and in a young multi-graft tree also suggests that plant growth regulator interaction from the other flowering cultivars in the multi-graft is probably not significant.
Source of the budwood for Warren might make a difference (both trees came from Dave Wilson Nursery) and it might be worth considering getting some scion wood in future from CRFG. Local growing conditions can also dictate very different behavior. Bartlett grown in the Sacramento River delta is parthenocarpic; grown closer to the coastal areas it requires cross-pollination.
Certainly rootstock could make a difference too. I don’t know what the rootstocks were for these two trees but they were both dwarfing. It’s great to hear from the forum what rootstocks have worked for other people and that might be something I can look into at CRFG too.
This Warren was planted in March of 2019 as a companion to two Orients. All were nice 5-6’ trees with well established roots in a 5 gal container when I bought them from Bob Wells Nursery in Mineola, TX, a family owned business I highly recommend. All are about 12’ after pruning the whips last month. They are in full sun in sandy loam on a slope. They were lightly blighted a couple of years but I stopped that with a better dormant oil spray cycle, including copper. The lady in the pic is 5’ 2”, and the reason I have 3 pear trees. These 3 have been the least problematic of the trees in my orchard.