Adriano, at the time most of our stone walls were built in New England, most of the settlers at that time were English or German. The Irish immigration came a little later (main Irish immigration occurred with the Irish Potato Famine in the mid-1800's - 1/2 the population of Ireland immigrated to the United States at that time), so most of those early walls, which were built starting in the early 1600's through mid-1700's were by English and German immigrants. And a few Dutch as well Later, the Scots (surge of immigration occurred after the Battle of Culloden in 1746 and the subsequent and infamous Highland Clearings that occurred for the next 20 years or so in the Scottish Highlands) who are no strangers to stone walls, and Irish immigrants came over, and if they settled in this part of New England, where the soils are very stony and rocky, they, too, were almost forced to create this stone walls, just to be able to clear the soil enough to farm and graze livestock. Very interesting part of our early United States history, and many of these stone walls still exist, and have been lovingly preserved.

http://www.stonewall.uconn.edu/PrimerFAQNew.htm

Patty (whos maiden name is a "Fraser" and proud to be from one of the greatest Highland Scottish clans)

I have about a 1/2 mile of stone walls running through the forest on my land here in Maine...one of my favorite features, I wish there were more. I've always heard that the Irish were a big part of their construction. Irish immigrants did make up a major proportion of the indentured servents in the 1600's and 1700's, so this may well be true. I hope I can leave something as lasting as these walls. Maybe a few walls of my own...hopefully some citrus trees that will surprise people when they stumble across them

Mid March Update time.

Outside weather (March 1-15):

-So far in March the lowest outside temp has been 20F (-6.7C). This occurred yesterday morning it was 11F (~6C) below the average low for the day. Brrr...
-The high temp so far has been 53F (11.7C)
-The daily average temperatures have been between 29.9F (-1.2C) just yesterday and 45.7F (7.6C) with most days in the mid 30's (0-3C). Only 3 days have had an average above 40F (4.5C)
-The soil temperatures at a depth of 4" (10 cm) have mostly been around 30-35F. The current soil temperature is 32F.

Inside temperatures:

-The coldest inside temperature so far in March has been 33.0F, which occurred on 3/10. The enclosure was still buried in snow after our unexpected March snow storm that dumped ~16" (~40cm). For comparison, the big snow storm in Feb. deposited ~26" (~66cm) of snow.
-The sun angle is noticeably higher. On sunny days the high temperature in the enclosure has typically been over 60F (15.5C). The highest inside temp was 77.0F (25C)
-The soil temps at 4-6" depth have been around 41F (5C). The highest soil temp was 42.6F (~6C) on the 14th just before the cold-temps moved in.
-The daily average internal temperatures have ranged from 34.6F (1.5C) to 48.4F (9.1C). The majority of the time, the daily average has been above 40F (4.5C).
-The largest temperature differential between the inside and outside was 14.4F (7.9C) on the 14th

Here is the Early St. Ann on March 13:



Now for the shocker!


It looks like it is getting ready to start a growth flush soon! I was not expecting to see this. Hopefully it will flower.

For comparison here's my Armstrong Early (pics taken same day), which is inside in my south facing sun room. I wonder how long it will take the Early St. Ann to look like this?

Forgot to add this link:

http://www.crec.ifas.ufl.edu/academics/classes/HOS6545/pdf/young_1981.pdf

Interesting paper investigating the relationship between winter hardening temperatures and spring bud break in several different citrus varieties.

It seems citrus that undergo strong winter hardening break dormancy earlier than those that do not experience such cold temperatures in the winter. This is true even for Flying Dragon.

"In general, leaf bud break required more time after growth temperatures occur­red following mild winter hardening temperatures (147 hours at or below 7.2°C) than following cold winter-hardening tempera­tures (752 and 762 hours at or below 7.2°). Flower bud break followed similar trends."

Also, the authors suggest Eremocitrus glauca (Citrus glauca) as a good candidate for development of edible cold hardy citrus:

"This later spring dormancy and increased cold hardiness of F1 hybrids of E. glauca and the knowledge that the fruit are nearer to being palatable than F1 hybrids of P. trifoliata' indicate that E. glauca is an excellent parental candidate for use in the develop­ment of new cold-hardy scion cultivars."

That info is interesting & useful, thanks Scott.

BTW: My Unshiu mandarines (satsuma) shows no activity yet.

Scott, you did a great job in protecting the tree over the winter. It seems to be the flower, doesn't it?

Ivica, I was not expecting to see any signs of growth on my St. Ann for at least another month... quite surprising! I thought the observations from the research paper were very informative too!

Thanks Igor, yes it would be nice if that was a flower bud, but I'm trying to to get my hopes up too much. I am quite curious to see how quick (or slow) the new growth is in comparison to my indoor potted plants.

With my long range weather forecast, I will probably have to wait at least one or more likely two months before taking down the citrus enclosure...

Thanks for the update Scott. In that study the soil temps were quite warm during winter. I'm surprised your Citrus are breaking dormancy already since our soils are still very cold. I'll have to check my Citrumelo to see if there are any signs of life.

Yes, the soil temps are comparatively warm in that study. Containerized citrus should be fully dormant at my current soil temps. However, my measurements are at 4-6 inches in depth, the roots of my tree should extend down at least 12" or so after being in the ground for one season. At least some portion of the roots should be in soil that is warmer. But, at this time of year, you would probably have to go down ~2 ft to reach soil that is in the 50+ F range.

Whatever the overall soil temps are in the root zone, it is clear that they are warm enough to support at least some reduced level of metabolic activity and growth in the canopy.

I'm guessing that any future growth will be quite slow, at least until the soil temps increase to around 50-55F and the average daily air temps are similarly high. It will be interesting to see what the temps are when it begins to take off... time will tell.

Except for the tap root (only if the tree was started by seed planted in the ground) 90 - 95% of a citrus tree's roots are only in the top 20 inches of the soil. This root depth also applies to old trees. - Millet

I didn't see any growth on my Citrus yet.....

Citrumelo 'Dustan'


A first year seedling of Poncirus trifoliata 'English Large'...no winter damage.

Tim, the Dunstan is looking pretty good considering what it's been through this winter.

I assume the Poncirus is in one of your winter enclosures, is it heated? Funny that it hasn't lost many of its leaves, the first year my Flying Dragon was in ground it was nearly 100% evergreen.

Hi Scott

I'm very impressed with the Citrumelo 'Dustan' since we lost power during a storm and the temperature dropped to -2.9F(-19.3C).

I have 4 Poncirus trifoliata 'English Large' seedlings outside with no protection at all as a test to see if they can survive as first year seedlings. All four look very green with no cold damage. My larger PT tree looses all it's leaves in fall.

End of March Updade:

This will probably be the last update... I might add one more when I take down the enclosure and/or bud break occurs.


Outside weather:
-The low temp for the month was 19F (-7C) on March, 18.
-We had below avg. temps from the 14th to the 21st.
-The high temps on the 18th and 21st were just barely above freezing. 34F (1C) both days.

Inside the enclosure:
-There were no sub-freezing temps inside the enclosure.
-The low temp for the month was 32.4F on 3/18
-Soil temps at 4-6 inches were generally in the low 40's bud did dip into the upper 30's during the middle of the month.
-In general the interior low temps (air and soil) have been 5-8F (2.5-4.5C) higher than the corresponding outside temps.
-On the 31st the low soil temp was up to 44.7F (7C)
-The monthly graph shows high temps in the upper 80's to 90's (27-32C). But this is not correct. The temp. probe is not shielded and with the higher angle of the sun, the sensor now receives direct sunlight. I have another temp sensor (w/ no data logging) that is better positioned. The highest I've seen on this probe was 74F (23C) when the other unshielded sensor was reading 90F (32C).
-The last several days, the daily average temps inside have been in the low 50's (10-13C).






Tree looking pretty good, not a single leaf dropped during the entire winter!


No new visible growth on the buds (as compared to the last update in mid March)... not surprising since we had a week of colder weather after the middle of the month. Hopefully I do not have too much longer to wait.

Your Citrus look great. I hope this cold weather breaks soon........Hopefully we'll some Magnolias start to bloom in the next week?