Ground cherry improvement Europe

Adaptation Projects
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Ground cherries is interesting new crop to domesticate, but unfortunately domesticating in many cases is like looking for a needle in a haystack. I can sow tens of thousands of seeds to look for the most cold tolerant, but besides that the most interesting traits are only evident later in their life cycle when I don’t have as many plants. That’s why it would be good to have as many people growing as many plants and looking for interesting traits. This community might still small to easily find significant mutations, but it’s more likely than me byself. This year I had some 30-40 mature plants and I don’t think I will have more than 100 in the near future.

Traits that I find interesting are fruits size, lobes in the fruit, amount of petals (latter 2 are related to fruit size), amount of fruits in leaf nodes and possibly some growth habbits, although not sure what would be best. Fruit not falling once they are ripe would be useful as well, but that might be hard as it either is or is not. Fruit size could be improved incrimentally by several different mutations.

This year I thought I would really make the effort and try to select for the biggest fruits. For that I bought a precision scale (only 20€). I’m selecting for earliness and fruits size so I first saved a patch of the earliest fruits. After that I have started to scale every bigger fruit and selected the biggest. At the monent I have had cut off at 3.5g. There has been one plant that is doing clearly the biggest fruits; almost all over 4g when otherwise there haven’t been many over 4g. I don’t know if that one plant is special or if the size is relateted to the fact that it doesn’t have as much competition. I still save fruits from that plant separately. I save all over 3.5g to keep some variance and try to slowly move the limit up in the coming years.

Biggest fruit still didn’t break 5g, but fruits have gotten bigger the more ripens. I have picked them daily and some have been little underripe because they have ripened so fast over the last few days with warmer weather. I try to avoid that they fall to the ground where they are more easily accessible to rodents.

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Only 2 fruits that i picked from plant that makes the biggest and 2 of the bigger fruits from all the rest. Mostly fuits aren’t even that big and 2-3.5g is more common size.

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Just slightly smaller than 1€ coin.

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I would also be interested in interspecific crosses beyond grisea/pubescens/pruinosa complex. I have tried cross with angulata, but only got 2 seeds that didn’t germinate using angulata as pollen donor. Not sure if embrio rescue would work and if it after that could be used to make back crosses. So I don’t think I will use effort to make those before I have some information if it’s worth the effort. There should be some other species that cross more easily, but it seems to be hard to find any information about it.

Ps. I might have little weird consept of having fun, but I find it exciting to go through fruits and weighing them with a precision scale. It’s like a little treasure hunt. I could take thousands of fruits, weight and sort them by weight. I don’t think there will be that many once I make the final harvest, but should be at least several hundred. It’s even more interesting coming years when I try to see if I can improve on the biggest.

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I am growing some Giant Cape Gooseberries developed by Cicada Seeds in Canada. This is the description from their online catalogue.

Giant Cape Gooseberry Mix Seeds

Cape Gooseberry is a delicious fruit native to South America. It is also called goldenberry, Peruvian groundcherry, Inca berry, aguaymanto, uvilla or uchuva. I find these to be much tastier than regular ground cherries (eg Aunt Molly’s). They taste like a sweet and tropical pineapple with hints of vanilla. They barely have any tartness like regular ground cherries.

In the winter of 2023/24, I sourced as many giant and extra sweet varieties of cape gooseberry that I could find from around the world. I grew them altogether, and they produced the largest and tastiest berries I’ve ever eaten. One of the largest berries was 12.3 grams!

These berries require a long season, so I’d only recommend them for folks with long seasons and/or greenhouses. On Vancouver Island, I start these earlier than my tomatoes around early February, and plant out in my unheated greenhouse in April/May. The plants will have ripe berries from late August-October

The round orange fruits grow inside a papery husk. You can tell they are ripe when the husk (calyx) turns tan and papery. Wait until they are fully ripe to eat and they will have a very sweet, tropical fruit flavour with a hint of vanilla. You can even leave them on the counter for a few days or several weeks for an even sweeter taste.

These fruits will actually last for several months in their papery husks on the kitchen counter without any preservation. They make a delightful tropical treat in January!

A shared some with a friend this summer who is an avid foodie and world traveler. He knows the best restaurants in every major city in the world. He said this was the best thing he’d eaten in years!

Cape Gooseberries are fabulous eaten fresh off the plant, as a garnish on fancy desserts, in baking (think cape gooseberry upside down cake), salsa, jam, cocktails, fruit salad, or dried. I like to think of them as “northern pineapples” because they can be used somewhat like a pineapple substitute.

Unlike regular ground cherries that are low growing, Cape Gooseberry is tall (up to 8 feet), which makes picking the fruits much easier. It produces a lot of biomass (leaves and stems) which is helpful for composting in the permaculture garden. Don’t give them the most nutritious soil so they put more energy into berries and less into leaves.

I grow these as annuals, but a friend of mine has overwintered them successfully in Victoria, BC by adding a foot of straw mulch for winter.

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I’m aware of these, but I’m specifically interested in ground cherries, not cape gooseberries. They don’t work well in my short season. I don’t know which might be easier; breeding cape goose berries to be month earlier (like ground cherries are) or getting ground cherries to produce big fruits like some cape gooseberries. I have already quite many crops where cold tolerance/earliness is an issue so it’s nice to have something that grows fairly well as it is and challenge is a little different. Personally I also like the taste of ground cherries more. To me it seems that when people complain about the taste of ground cherries they haven’t waited until they are ripe. They are a lot sweeter than cape gooseberries and have no tartness.

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In my part of the world, cape gooseberries are considered one of the ground cherry species. Are there other species within Physalis besides Physalis peruviana which are not considered ground cherries in your region?

I have talked so some people in the United States who refer to everything in Physalis as a ground cherry except Physalis ixocarpa and/or P. philadelphica. So I know there are some differences in thought about this topic.

In my work on Wikipedia, I came across information suggesting that there are P. peruviana populations with three different ploidy levels. Maybe the polyploid are “less” ground cherry than other members of the genus because they are less able to spontaneously cross with diploid species.

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If I’m not wrong it’s the official separation and they might be more generialized in general population (is generally is when things look alike, hence several “salmon” that aren’t related to salmon). Ground cherry name comes from the fact that they fall to the ground. Cape gooseberry don’t fall (at least not as easily), hence they are not ground cherries. There is also the differences in region of origin. I just watched an online lecture about breeding both types and I’m quite sure she used the same logic to distinguish those two types.

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Very interesting. I have grown cape gooseberries at least two years. I’m certain that they fall to the ground the same as other Physalis.

As far as I know the “tomatillo” species are the only ones in the genus that don’t necessarily fall to the ground, but they are often harvested green so that seems kind of consistent. I’ve read a fair amount about Physalis species and breeding, but I don’t think I’ve ever heard of a nomenclature distinction between ones that fall to the ground and ones that don’t.

I have never thought about the origins of the name ground cherry, but I would have guessed it is a “ground” cherry because they don’t grow on cherry trees. Husk cherry is another name I’ve heard.

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I think they might fall to the ground, but it’s not as clear as with ground cherries that fall straight away when they ripen or even before (although some species that have ground cherry in their name like angulata don’t fall to the ground, but generally it seems to refer those more common species that do so). That was one of the traits they wanted to improve and made a clear distinction to cape gooseberries. Can’t remember the name of the lecture, but I’m sure I saw it here first. I’m quite certain it’s official(ish) scietific distinction and every thing else is what’s been muddled by internet. Just quick googling gave one site which said ground cherries (p.pruinosa) also known as cape gooseberries. People just tend to generalize things that look the same.

Personally I wanted to concentrate on grisea/pubescens/pruinosa and their closer relatives. Peruviana is a little isolated as it doesn’t cross with (as far as I know) any of the ones from Mexico area and I don’t know if it even crosses with some species closer to it’s range. So it kinda self eliminated itself.