Ripening figs in cooler climates

The house that we purchased and moved into last spring came complete with a gorgeous, huge fig tree. It is currently full of gorgeous, huge figs, all rock-hard. It is planted against a south-facing wall, so it gets lots of reflected heat, but of course that is diminishing by the day.

So two questions:

1) Is there anything we can do to encourage at least a few figs to ripen before it is too late and

2) Is there anything worth doing with under-ripe figs?

I found information originally published in the summer 2009 issue of Edible Toronto about ways to increase the chances of figs ripening on the tree in cooler climates. In an article (no longer available online) entitled “Fig Fetishists in Ontario” author Steven Biggs says:
“The real secret to coaxing the fruit to ripen in our climate is to gain a few days of ripening time. Ferreira shows me a couple of trees over which he’s draped clear plastic bags. This creates a warm microclimate around the tree, helping it to come out of dormancy more quickly. Once the current year’s growth is underway and figs are forming, another trick is to break off the tip of the branch, leaving four leaves on the current year’s growth.

What’s Ferreira’s big secret? Extra virgin olive oil. In the first week of September, he looks for figs that don’t seem as if they will ripen before winter, and puts a drop of extra virgin olive oil on the eye. After six or seven days, he repeats the step. While this doesn’t work on all of the fruit, he says, it helps some to ripen.”

Most sources warn against using unripe figs. Not only would they not be tasty, but according to the Purdue University’s New Crop Resource, “the latex of the unripe fruits and of any part of the tree may be severely irritating to the skin […]It is an occupational hazard not only to fig harvesters and packers but also to workers in food industries, and to those who employ the latex to treat skin diseases.”

Ficus carica, Fruit ripening

harvesting and storing pear fruits

I have several pear trees. I’m never sure when to pick the fruit–should it be picked when ripe, or can it be picked sooner and allowed to ripen off the tree? Any advice on storage after harvesting would also be helpful.

If you have European pears, and not Asian pears, they are best picked before they are fully ripe. University of California, Davis Integrated Pest Management has basic information on harvesting pears. Excerpt:
“European pear varieties ripen best off the tree. Fruit that is left on the tree doesn’t develop full flavor. Pick the fruit when it is green and hard but of mature size for the variety. The stem should break off the spur easily when the fruit is twisted upward. If the spur breaks off the tree, the fruit is not ready to pick. Allow the fruit to ripen in a cool place in a fruit ripening bowl or paper bag. You may store fall-ready varieties for several weeks in cold storage (below 40 degrees F) and bring them out for ripening at room temperature.

Asian varieties should be allowed to ripen on the tree. The fruit will generally turn from green to yellow and the flesh should be sweet and juicy. Asian pears will hold on the tree for quite a while after they have ripened. It is better however, to keep them in cold storage until ready to eat. Asian pears can be stored for several months, depending on variety.”

Oregon State University Extension has an article by Robert Stebbins and others (Picking and Storing Apples and Pears) listing different varieties of pear (and apple) and the best times to harvest and their average life in storage at different temperatures.

Here is more on picking and storing pears from a no longer available article by Carol Savonen with information from Oregon State University Extension agent David Sugar.
Excerpt:
“Pears picked when slightly immature will ripen with better quality than pears that are over mature when picked. To tell if a pear is mature, a general rule of thumb is that, while still on the tree, most mature, ready to ripen pears will usually detach when ’tilted’ to a horizontal position from their usual vertical hanging position. Bosc pears always are difficult to separate from the spur.

“Unlike apples, which are ready to eat from the day they are picked, pears must go through a series of changes before they can deliver their full splendor,” explained Sugar. “Pears do not ripen on the tree to our liking. If allowed to tree-ripen, pears typically ripen from the inside out, so that the center is mushy by the time the outside flesh is ready.

“Commercial pears are harvested when they are ‘mature,’ he continued. “In pear language, that means they are picked when they have reached the point where they will ripen to good quality, sometimes with a little help, but definitely OFF the tree.

“‘So the frequently heard notion that pears are picked when they are still hard and green as a convenience for enduring the long truck ride to market misses the point,’ Sugar quipped.

“Once commercial pears are picked, growers cool them down to about 30 degrees F. They don’t freeze at this temperature, because the fruit sugar acts like an antifreeze.

“‘The colder the pears are, the longer they’ll stay in good condition,’ said Sugar. ‘In fact, they actually need to be cooled in order to ripen properly.’

“Bartlett pears need to be cooled only for a day or two, and winter pears such as Anjou, Bosc and Comice require 2 to 6 weeks for optimal effect, he said.

“‘Without this chilling process, a mature picked pear will just sit and sit and eventually decompose without ever ripening,’ explained Sugar.’Pear ripening must be closely watched (…) There is a relatively narrow window between “too hard” and “too soft” where the perfect pear texture lies.’ Sugar recommends ripening pears at 65 to 75 degrees F for the following times: Bartlett, 4 to 5 days, Bosc and Comice, 5 to 7 days; and Anjou, 7 to 10 days. The longer the time the pears have spent in cold storage, the shorter the time to ripen them. ‘As ripening begins, pears produce ethylene gas, a ripening hormone, inside the fruit. This speeds the ripening along. The ripening time gets shorter as the time since harvest passes.’

“Pear lovers can ‘kick start’ the pear ripening process by putting freshly bought or newly harvested pears in a paper bag with a ripe banana or an apple, both of which give off copious quantities of ethylene gas. The bag keeps the gas near the pears, which soak it up and quickly begin producing their own.

“How do you tell when a pear is ripened to perfection? ‘Hold the pear gently but firmly in the palm of your hand, as a baseball pitcher might hold the ball while studying signs from the catcher,’ recommended Sugar. ‘Apply the thumb of that same hand to the pear flesh just below the point where the stem joins the fruit. When the flesh beneath your thumb yields evenly to gentle pressure, it is time to eat your pear. If you have to push more than slightly, it is not ready yet.'”

on picking avocados

What causes an avocado to have a foul taste even when it looks superficially just fine? I’d like to know if there is a way of telling simply by looking at them, so I can avoid buying bad ones.

According to the book, Fruit & Nuts by Susanna Lyle (Timber Press, 2006), there are three main varieties of avocado: Mexican, Guatemalan, and West Indian. Mexican fruits tend to be smaller, with thin skins that turn a glossy deep green when ripe. Guatemalan fruits are round or pear-shaped and have pebbled skin. The largest avocados are West Indian, nearly round, with shiny green skin and flesh that is less rich in oil.

Avocados tend to take a long time (sometimes over a year) to reach maturity from the beginning of fruit-set, and sometimes they will not soften and become edible because the stems have a ripening inhibitor. For this reason, they must be picked while still hard, and then allowed to ripen at room temperature. Mexican fruits ripen fastest (6-8 months) but have a shorter storage life. Guatemalan fruits take 12-18 months to ripen and must be stored at about 10 degrees Fahrenheit for over a month.

This factsheet from U.C. Davis about post-harvest quality in avocados describes optimal storage temperatures, and mentions several variables that can lead to an unpleasant flavor:

On-tree storage may result in development of off-flavors or rancidity with overmaturity
Off-flavors may also develop when fruit are harvested during periods of hot weather
>10% CO2 may increase skin and flesh discoloration and off-flavor development, especially when O2 is <1%
Anthracnose: Caused by Colletotrichum gloeosporioides and appears as the fruit begins to soften as circular black spots covered with pinkish spore masses in later stages. Decay can penetrate through the flesh and induce browning and rancid flavor.

There are several scientific articles that discuss heat-induced off-flavors. In one example, “Isolation of Unpleasant Flavor Compounds in the Avocado (Persea americana)” by Brian I. Brown, certain varieties seem more prone to bad flavors than others, and some varieties lose the off-flavor once they are fully ripe.

I’m afraid there does not seem to be an easy way to know in advance which avocados will taste bad. Certainly, you should avoid fruits with dents or obvious discoloration in their skin. You might also complain to the market where you have purchased inedible avocados, and they can relay that information to their distributors and see if it has something to do with how the fruit is harvested or stored.

on harvesting red currants

I have picked my red currants. Some berries on the bunches are still green. Is it possible to ripen them in the house?

Most sources say that you should pick entire strigs (the name for the bunches of fruit) when they are fully ripe. I don’t think the green currants will ripen successfully indoors. However, currants which are to be used for making preserves may be picked slightly before full ripeness (but not when green), according to an archived article on fruit harvesting, published by the University of Idaho Extension:

“Currants may be harvested two or three times, but all of the fruit from a particular cultivar is usually harvested at one time. Wait until all of the berries on the bush are ripe. Berries at the tops of the fruit clusters ripen before those at the tips. Harvest the fruit after it softens and is fully ripe, but before it begins to shrivel. […] Pick the fruit by pinching off the fruit clusters (called strigs) where they attach to the stem. Particularly with red and white currants, do not strip the berries from the clusters.”

University of Illinois Extension has similar recommendations (link no longer available):

“Currant: For eating out-of-hand, currants should be dead ripe and picked just before eating. For making jam and jelly, however, pick them when they are firm but not fully ripe. Pectin content is high at this stage. Currants have a naturally high pectin content and thus are excellent choices for jelly- and jam-making. To harvest currants, twist the cluster off of the branch first, then strip the berries from the cluster. Don’t attempt to pick the berries one-by-one.”

on fertilizing and pruning grape vines

My grape vine is about 8 years old. Every year the grapes fall before they are ripe, around late July. The plant looks very healthy and has a lot of foliage. It is growing horizontally on several cable lines against a concrete wall. I don’t water and fertilize the plant much except for half a bag or a bag of manure in mid- to late winter.
At first I thought the fruit wasn’t getting enough sun, so early on, I cut all the leaves around the grapes, but they all fell off the vine from mid-July onward.
I prune the grape vine very aggressively in fall, leaving only several year-old branches with several buds on them. The vine is very healthy and grows about 30 feet a season. Could the problem be due to too much foliage?

According to The Grape Grower by Lon Rombough (Chelsea Green, 2002), the premature dropping of fruit is called ‘shatter,’ and excessive shatter can be caused by nutrient deficiencies. It’s normal for a certain amount of unfertilized berries (i.e., grapes) to drop a week or so after the bloom stage, but dropping of fruit in July is a problem.

I wonder if you are giving them overly rich soil (by adding manure). If the manure is high in nitrogen, this encourages a lot of leafy growth, often at the expense of flowers and fruit. I grow grapes and have never fertilized them. The book mentioned above says not to apply fertilizer unless you know there is some kind of deficiency. Note in particular this quotation from the book:
“Excess nitrogen causes flower clusters to ‘shatter’ (flowers fall off), reducing fruit set. In fact, mature vines should not need any supplemental nitrogen when grown in a healthy soil with plenty of organic matter. A good general rule for fertilizing grapes is to use a mulch of well-rotted compost, which will supply small, but regular essential amounts of nutrients.”

Also, the usual time to prune grapes is in mid- to late winter–I do mine in February. Pruning in the fall may be contributing to the problem your vine is having with poor fruit set.