Lychee in So Cal 2018

[Meo]

This winter is very dry and warm for us, temp rarely below 70F.  I guess there is not much chance for lychee to bloom and fruit this year?  Is there anything that can help lychee to bloom when it’s too warm?  Let’s hear from other folks with lychee!!  Thanks

[barath]

No idea if this will help, but I've heard of people dumping a bag of ice around their deciduous fruit trees to trick them into thinking it was winter.  (Not sure if this is a good idea for lychee.)

[Ulfr]

This winter is very dry and warm for us, temp rarely below 70F.  I guess there is not much chance for lychee to bloom and fruit this year?  Is there anything that can help lychee to bloom when it’s too warm?  Let’s hear from other folks with lychee!!  Thanks

Other than pruning at the right time I’m not much help. What varieties do you grow?
Out of interest Where are you located? Good microclimate? I checked the data records for Southern California and see the low on most days is well below 60, often below 50. Average high was also below 70? Temps look ok for flowering

[Frog Valley Farm]

🗯

[SoCal2warm]

Think on the positive side, even if there's no fruit it should still be a very good growth year, which is good because lychee trees are slow growers (especially in the SoCal climate). The bigger and more mature the trees become, the more proclavity they will have for fruiting later.

[simon_grow]

Yes, our nightly lows around this time of year is in the 50s or lower. It should be a decent crop of Lychees in SoCal this year. If a tree bore heavily last year, there may be little or no crop this year but if a mature tree that is well cared for didn’t bear much fruit last year, there is a good chance for a nice crop this year if the grower did everything correctly.

Trees can be encouraged to bloom and hold Fruit by giving it the right care at the appropriate time of year which depends on where you are growing. Lycheesonline.com has great info for people in Florida but the pruning dates don’t correspond with our climate here in SoCal. Take good notes on your trees because blooming times are variety specific and even with the same variety, it can change from year to year.

Some drought stress pre bloom may encourage more blooms and leaf nitrogen levels dropping below a certain percentage may also help with blooms. Nitrogen should not be givin late in the season. Once blooms have pushed and Fruit has set, proper fertilization at the correct stage of growth may decrease Fruit drop. There are several natural rounds of fruit drop for Lychees and girdling branches is another way to increase yields.

Lychees are ready for harvest at different times of the year depending on the variety and specific region/microclimate. Around my area, some of the Lychees like Sweetheart/Hak Ip are ready around September and Brewster is ready shortly after around late September into October IIRC. In order to encourage blooms, the trees should be harvested with some of the branch, about 12-18 inches depending on the pannicle size. Don’t just trim branches with fruit, you can synchronize the flush by giving the whole tree an even trim and this will also help keep the tree from getting too large.

There’s a lot of great information out there if you perform a google search. I found some Australian sites with very detailed information that may be too much for the average grower but very informative non the less. Proper pruning and fertilization can have a significant affect on yield.

Simon

[Meo]

Thank you for all the informations!!!  I looked up somewhere and it mentioned that lychee needs daytime high to be lower than 68F for blooming so I was a bit worry.  The avg low at night lately has been about 55 for me, hopefully that works.  My tree is very young only about 4ft, I was just hoping for a few fruit so I can  figure out what variety it is.  If not then a good growing season might be even Better!!

[simon_grow]

Four feet is a pretty small tree so even if it blooms, it may not hold any fruit although it’s absolutely possible. Small Lychees tend to not hold much if any fruit unless it has some underlying health issues that are killing the tree. The opposite is also true so if a small plant is very well taken care of with proper care, pruning, drought stress mulch, it can also fruit at a small size. Some varieties like Groff and Emperor are a bit more likely to hold fruit even at a small size.


The temperatures given in literature are rough estimates and some varieties require more or less cold stimulus. It is believed that temperatures above a certain range which I can’t remember at the moment will deduct from the total accumulated chill hours required to stimulate blooms. The maturity of the current(last) flush can also influence the balance of hormones within the plant to tilt more toward vegetative growth, partial blooms or full bloom.
Simon

[andrewq]

everything that simon said.

i also went looking for the chills hours and threshold and online resources cite different requirements, so i take these website with a large grain of salt.

one scientific manuscript cited that temperature drop when new growths were small (1cm i think?) stimulates bloom. they did it by growing container lychees in a greenhouse and moving them outdoors at different stages of development.

tip pruning new growth if you anticipate a cold front in 2-4 weeks might work. don’t prune old growth.

[Pasca]

I have a mature Sweetheart in the San Gabriel Valley area.  I have had it in the ground for about 11 years.  It is now about 7-8 ft tall and about that size wide with a large drooping canopy.  No matter how to try to shape it, the new growth keeps drooping to the ground especially when they hold fruits.  The first 6-7 years, I would get inconsistent blooming and may be lucky to get one fruit.  The last 2-3 years, the blooming is more regular.  Right now, there are many panicles of flower buds, even with the dry winter that we have had.  Last year, I had a good harvest.  I think the cool spring in May and early June 2017 helped the fruitlets to hold.  Usually, the heat of late May to early July just beat up on the fruitlets and they would drop like flies.  As you know by now, growing lychees in Southern California is a challenge.  If it would be easy, you would have seen locally grown lychees in the markets some time ago. 

Your tree being 4 ft tall is just too young.  I would just enjoy it growing and give it time.  If you are like me, you would get rewarded in due time.  Surprisingly, my lychee tree has grown quite well.  The major wind storm 6 years ago caused some large branches to break.  But it has recovered well since then.  The tree branches are quite weak.  A heavy sustained wind can easily snap a branch or two.  Good luck.

[gozp]

I have a mature Sweetheart in the San Gabriel Valley area.  I have had it in the ground for about 11 years.  It is now about 7-8 ft tall and about that size wide with a large drooping canopy.  No matter how to try to shape it, the new growth keeps drooping to the ground especially when they hold fruits.  The first 6-7 years, I would get inconsistent blooming and may be lucky to get one fruit.  The last 2-3 years, the blooming is more regular.  Right now, there are many panicles of flower buds, even with the dry winter that we have had.  Last year, I had a good harvest.  I think the cool spring in May and early June 2017 helped the fruitlets to hold.  Usually, the heat of late May to early July just beat up on the fruitlets and they would drop like flies.  As you know by now, growing lychees in Southern California is a challenge.  If it would be easy, you would have seen locally grown lychees in the markets some time ago. 

Your tree being 4 ft tall is just too young.  I would just enjoy it growing and give it time.  If you are like me, you would get rewarded in due time.  Surprisingly, my lychee tree has grown quite well.  The major wind storm 6 years ago caused some large branches to break.  But it has recovered well since then.  The tree branches are quite weak.  A heavy sustained wind can easily snap a branch or two.  Good luck.

Would love to see photos of your Lychee Tree.