Harper is Zone 7b/8a with 700 – 800 chilling hours.
Northern standard sweet cherry varieties aren’t reliable in Texas (most requiring 800-900 chill hours), but there are two sweet cherry varieties that produce well in Texas, both available at Womack and Bob Wells. (Note that soil alkalinity or acidity may be a factor.)
Most sources say that cherries are marginal, at best, in the hill country.
Try Stella and Lapins, if any.
Minnie Royal Cherry
200-300 chill hours, zones 6-10. Medium-sized red sweet cherry; firm with good flavor. Tree is very productive with a low chill requirement. Pollinated by Royal Lee. 400-500 chill hours. Try to get Colt rootstock rather than Mazzard, because of alkalinity. Womack $19.00, Bob Wells 39.50
Royal Lee Cherry
200-300 chill hours. Zones 6-10. Medium – large red sweet cherry; heart shaped, very firm with excellent flavor. Tree is very productive with a low chill requirement. Pollinated by Minnie Royal. 400-500 chill hours. Womack $19.00 Bob Wells 39.50
Since the Harper area has more chilling hours, it might be worthwhile to try some other varities.
- Zones: 5-9, Chill hours: 700, Bloom Time: Mid-Season (Based on typical Central Valley California weather)
- Harvest: May 20 – June 10, Large, yellow with a red blush. Distinctive yellow flesh. Considered the sweetest of all cherries.
- Facts of note: Dave Wilson’s Taste Test Top Scorer. Favorite in colder regions. This premium cherry fetches top dollar at market. The cherries are very sensitive to temperature, wind, and rain while ripening. Developed in 1952 at Washington State University by Harold Fogle. It is a cross between the Bing and Van cultivars.
- Pollination: Pollinated by Van, Black Tartarian, Bing.
500 hrs, zones 4-9. Tart cherry. Ripens early June. Bob Wells
- Bloom Time: Very Late (Based on typical Central Valley California weather)
- Harvest: May 25 – June 20
- Looks: Large, light red skinned fruit with yellow flesh.
- Sour cherry, perfect for cobblers, pies.
- Favorite in colder regions. The most popular sour cherry in the United States and Canada. Extremely winter hardy tree. Known for heavy bearing. Named for the Montmorency valley in France.
- Pollination: Self-fruitful.
Self-fruitful, dark red sweet cherry from Canada. Large, firm, good flavor. Similar to Van in color, Bing in shape. Sometimes sold as ‘Self-fertile Bing.’ Ripens 4 days after Bing. 400 hours or less. USDA Zones 5-9. Ripens early June. Bob Wells 29.50
700 hrs, zones 4-8. Ripens very late. Self-fruitful. Bob Wells 19.50
Cherry Maturity Chart
Black Tartarian Cherry Tree (Semi-dwarf)
Mazzard -standard, has been used for more than 2,400 years.
Mahaleb – slight dwarfing effect, more disease resistant than Mazzard.
Gisela 5, most dwarfing commercially grown in Pacific NW. 50% of standard
Gisela 6, 12 rootstock, very cold-hardy.
Summer Pruning of Cherries to dwarf trees:
Núñez-Elisea is studying the use of summer pruning of trees on Mazzard rootstocks to learn if the technique can make a Mazzard tree compact and small, increase precocity, but still produce fruit of high quality. Previous work on young Regina trees on Gisela 6 rootstock showed that summer-pruned shoots produced less vigorous growth and more spurs the following year than shoots that were not pruned.
Initial results show that summer pruning can keep the trees about eight to ten feet tall—50 to 75 percent the size of a normal Mazzard tree. The number of flowers was also increased, he reported.
“There is an effect on precocity,” he said. “With summer pruning, we can produce more flowers.”
But there is a big if that he hopes his research will answer this season.
“Can we make big fruit?” he asked. “Based on the potential crop load and leaf area, my guess is that there is an adequate balance to achieve good fruit size.”
The summer pruning study began two years ago on two-year-old Sweetheart/Mazzard trees planted on a 12 foot by 18 foot spacing, with 202 trees per acre. The trial is located in Hood River at grower-cooperator Tim Annala’s orchard. Núñez-Elisea is comparing growth and precocity of trees managed by different summer pruning treatments that vary timing and severity of pruning cuts. The control trees are managed by the grower-cooperator as traditional steep leaders and pruned during the dormant period. The summer-pruned trees do not receive any dormant pruning.
Núñez-Elisea has already learned that tree size can be managed effectively with the summer pruning, which also encourages precocity. The control trees trained as steep leaders are an average of 11.2 feet tall with a canopy diameter of 9.7 feet, but the summer-pruned trees are half to three-quarters the size of the controls. He also observed that pruning cuts made by heading as compared to tipping produced smaller trees.
Heading is a more severe cut that leaves about one foot of wood after the cut is made. Tipping is considered a lighter pruning cut and removes only eight to ten inches of wood.
Summer pruning also reduced trunk size. The mean trunk cross-sectional area of the control trees was 73 cm2, whereas the summer-pruned trees were between 77 percent and 88 percent of the control size.
Núñez-Elisea also found that the type of pruning cut influences growth. Almost no new growth occurred after heading cuts made in August. Late summer tipping also resulted in no new growth in the same year.
The type of cut and pruning time also influences spur production. Tipping in early summer increased spur production by nearly 50 percent compared to controls and heading treatments, he noted. Heading in late summer produced fewer spurs than the controls.
The big test now is to see if the shorter Mazzard trees are still productive and yield large fruit.
This season, he will collect yield and quality data from the study, as it is the first year that the trees will bear fruit.
Summer pruning has an added advantage of being done during dry weather, reducing the risk of bacterial canker that can occur from pruning wounds made during wet weather.
Núñez-Elisea added that growers are excited about the potential development of finding a way to use Mazzard rootstock, yet keep the trees small. Dwarfing rootstock can be difficult to obtain from nurseries and is not inexpensive due
to royalties. Dwarfing rootstocks also require intensive management.
He envisions planting densities between 300 to 400 trees per acre, with yields of 30 to 40 pounds of fruit per tree in the fourth year.
Small trees also offer the benefit of being easier to net and cover for rain and bird protection, and there is potential to reduce pitting in the fruit because the shorter branches have less movement.
“There is a huge area regarding summer pruning that we don’t know much about in sweet cherries,” he said, adding that there are many questions about renewal wood, timing, rootstock and cultivar combination, canopy architecture, and such. “But I know that summer pruning works in keeping tree height down and promoting precocity.”