You can pick them once they are at a mature size. Limes are sold unripe in the stores, as a ripe lime is yellow not green.

The State of Florida's "official" maturity standard for limes is a minimum 1.75 inches diameter at the equator, or 42% juice by volume. But bigger is better, up until they begin to turn yellow, at which point the flavor changes, in my opinion for the worse -- it develops a rather flowery off-taste. So you want them while still bright green.

MM, are all limes yellow when ripe, or just the Persian? Thanks, Toni

You can pick them once they are at a mature size. Limes are sold unripe in the stores, as a ripe lime is yellow not green.

I should also add that we use the term "ripe" differently for citrus fruits than for, say, apples and bananas. Those fruits start out green and hard, with a lot of stored starch, and then, over a period of hours or at most a few days, convert much of that starch to sugars, change color from green to something else, and the cells soften, so a hard, crunchy fruit, becomes soft. That process is "ripening" in the true, physiological sense.

Citrus does none of those things. Rather, over a period of months, it very slowly converts acids (mostly citric) to sugars (about 1/2 sucrose, 1/4 glucose, and 1/4 fructose, in the case of oranges). They do soften somewhat, but not in the sense that a banana would. There is never significant starch present. And the color change in citrus occurs only on the surface of the peel -- the interior always was its final color.

Therefore, there is never a moment in time when a citrus fruit is "ripe." Rather, there will be a fairly long period in which it is good to eat, and perhaps a later time when it is even better. With oranges, mandarins and grapefruit, under Florida law, "maturity" is measured as brix (percent sugar), acid, and the ratio of the two, as well as juice content. When a fruit's test numbers reach certain levels, it is declared "mature." Once picked, most citrus do not continue to improve off the tree; indeed they tend to degrade in flavor. The one exception I know of is South African Clementines, which do increase their brix content and lower their acid content, slightly, after harvest, while on the ships to Europe.

In the case of the acid citrus (lemons and limes), they don't even get around to converting most of their acids to sugars. Instead, they may (in the case of 'Tahiti') develop odd, undesired off-flavors, when the peel color changes.

So, generally, 'Key' limes are eaten when yellow, but 'Tahiti' limes are eaten while still dark green, for the best flavor.

Doc,

I'm truly amazed. This has to be one of the best posts ever. I wish they had "sticky" posts as this could very well be the best and most concise piece of info I've read on limes (and lemons).

It's too bad they don't have that feature where moderators can make "Fruit FAQs" about each citrus. Maybe I missed something.

Eugene

Dr. Manners,

Your statement above that "the color change in citrus occurs only on the surface of the peel -- the interior always was its final color" is so not the case in my experience that I wonder if I'm misconstruing that remark, or if it was qualified in some way that I overlooked. To be certain, I just sliced through a mandarin that is approximately five months old. The peel is dark green of course, and the flesh is a pale greenish yellow. When mature the interior of these fruits is a typical reddish orange mandarin color. What am I missing? Thank you for any clarification.

Eddie,
True, there is some intensification of color, but no change in the base color. In the case of pigmented grapefruit, they're generally brighter red before maturity than later. I suppose if you go all the way back to 1/2" fruits, there would be little or no color inside, since there are no developed juice vescicles. But what I mean is, by the time there are significant juice vescicles differentiated and growing, they are already developing their final color. Everything in a citrus fruit except the peel surface color occurs slowly and continuouly, over months of time, rather than the 3-day ripen-up that a banana, avocado, etc., would do.

Kudos to MalcomManners. The first and most recent post (in this thread) about the ripening and "readiness" of citrus fruit is better described than I have read anywhere. I second the motion to have these added to the forum FAQ. Having operated a nursery for several years, I can attest to the fact that questions about the ripening of citrus are among the most popular list of inquirees among citrus hobbyists. Bravo and thank you.

My lemon/lime tree has green fruit,looks like a lime,is yellow inside and taste like a lemon??? did it cross polinate with a meyer lemon or is it a lemon tree? The tag is not on my tree. Its about 4 yrs old, as is a meyer lemon tree in same area. When should we pick our first crop????

I have what I believe to be a patio lime tree. This is the first year it produced fruit. The fruit is not shaped like a lime, but more like a squatty orange. I cut one open and it is orange inside and tasted interestingly like an orange. But it is deep green on the skin and has lime leaves on the plant! Is it just too soon to pick it? It hasnt matured into a lime inside yet?

Rangpur lime?

Its a mandarin called a lime because it's sour.

So for a Bearss should there be a bit of give when you squeeze? At optimum picking time?

I have a tree with a lemon tag on it and I have 11 fruits but they look like limes. How do I know what I have and when is the best time to pick them?

Lemons will look like limes when they are green. If you have some reason to believe you got a mislabeled tree, you can scratch and sniff the peel. Lemons will probably smell like lemons in my experience....at least after they mature up past say a golf ball size. To me, lemons have the best flavor when all trace of green is gone and the fruit is completely a good bright yellow. If it's still a little "seasick" looking, leave it another week or so to allow it to yellow out completely.

They're totally green but I will go down and sniff. Right now it's in a big pot in my dining room with plenty of sun. It even has new flowers coming out as well as the 11 maturing fruits. I'm afraid if I bring it outside it will get eaten by deer and gophers. I've worked so hard to get it to this point I don't want it eaten by anyone but me!

This is my first time reading through this old thread and am glad it was dug up. Very informative. Thank you Doc! (Does he ever post here these days?)

Good info as I also have a Bearss and it has a TON of limes. All the large dark green ones are really hard though, I was\am afraid to pick them too early.

I wondered, like hobbyartisan, if they should have a little give when ready to be picked.

Yes, Kelly they sure are productive aren't they! I have several Persian/Bearss lime trees and I prefer harvesting after they start lightening up and through the yellow color. When lightening / yellowing, they should be juicy, and in my opinion starting to get to their best flavor range. It is all about your own preference ! - Hey... my Delta Valencias turned green again! [but oh so good]

I do think they should have a little give when picked, otherwise they may not be juicy enough. My Persian lime is loaded with fruit this year.

I picked two so far but they got mixed in with store bought limes and I don't know which we've used. None were quite the light color yet so I'll wait. This is my first harvest with them. I got the tree when it was pretty small last spring so hopefully this year we have plenty! It's warming up here.

What a great thread! Thanks for reviving it, Laura! I didn't realize my Mexican and Key limes were the same plant! But I guess my Mexican sweet lime is a whole different fish!

Yeah. If you have both you might want to consider getting rid of one (Mexican and key) if you need space.

It turns out my plant was mislabeled. It's a lime tree NOT a lemon. I'm so disappointed. How do I prevent this from happening if I decide to get another plant?

Elena, can you upload a picture of your plant? I'd like to learn along with you and know what to look for when the more experienced folk pitch in.

I agree about the give and the slightly lighter colour, the lime in my avatar was my first one I ever grew and I got excited and picked it a bit early. It was a bit too dry inside. The zest was great though and I made sure to use it up entirely!

I have a question for 'elenahechtdesigns'- if you are keeping your citrus tree (or any pollinators) how IS this fruit getting pollinated? Are you doing so by hand or are these self pollinating. Learning much on this thread. This year we went from three months of severe drought to sometimes 6" of rain a day. Terrible on lawn. Great for weed invasion. Nutrients are washed away time after time. So many people having nutrients washed away. Thanks

My lime tree is indoors only because I've been told it's loved by deer and we have lots of them. I would actually like to eat them myself and not have them eaten by our wildlife. I use fishwater from our tanks to water it and it's thriving and constantly budding new limes.

Excellent article about how to choose limes! and how to keep the in the best way to can ejoy them later in whatever drink or plate you want. I also founded in another article to select it directly from the tree:

http://blog.marabellaproduce.com/2017/12/everything-about-fruit-picking-when-and.html

I also buy my limes at: http://marabellaproduce.com/ they have great and fresh products directly from Mexico. I totally recommend them.

Malcolm manners I really enjoyed your posts. Very clear, informative and delivered really well. Thank you. :)

Oh that post is from 2005. Haha well thank you none the less :)

Thanks Saltysea (Oz) -- I'm still around, but seldom post anymore -- too much potential for argument and unhappiness. But still here.

Oh wow lovely to see you still here Malcolm. Yes the internet can be a very "interesting" place alright. Lots of helpful, knowledgeable and kind people and then the others. I often wonder are those people as belligerent/entitled in real life. If I come across one i just think, well I'm thankful I'm not their poor spouse, sibling, colleague etc. :). Imagine having to deal with that in real life.

I also think that some people are probably ok in real life, they just get a bit brave hidden behind a computer.

Its a pity it has stopped you posting, but I understand your decision entirely. Hope you are surrounded by beautiful trees, lots of fruit and fragrant blossoms :). Hope you get to share your knowledge with others in person.

Malcolm, please come back. I have learned a lot from your posts and hope you reconsider.

Vlad

Yes, please post freely malcolm .... I echo Vladimir !