Why and how to grow ground cherries in your next summer garden

Last Updated on July 13, 2023 by Aaron von Frank

Ground cherries (Physalis pruinosa) are a delicious, easy-to-grow garden fruit native to Mexico and the southern United States. Although rare in modern gardens and markets, we think ground cherry fruit deserves a place at the top of the most esteemed local & native food lists. 

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Ground cherries aka husk cherries: the fruit that changed our lives 

If ever there was an edible garden plant near and dear to our hearts, it’s the ground cherry. After all, this little plant helped give roots to my and Susan The Tyrant’s gardening obsession many years ago…

It all started when we went to a friend’s house for dinner. That friend is Eliza Holcombe, who is lovingly referred to as “encyclopedia head,” due to her encyclopedic plant knowledge. Eliza is a permaculture teacher, Master Naturalist, and Master Gardener (she now works with us at GrowJourney), so her ecological knowledge is awe-inspiring.

Shortly after our arrival, Eliza took us on a tour of her garden. There in a corner of Eliza’s garden, we spotted dozens of small husked fruit on the ground under a squat shrub that I’d never seen before.

“What are those?” I asked. “Ground cherries or husk cherries as some people call them,” said Eliza. “Take the husks off and try some.”

My first taste of ground cherries

I happily obliged. My eyes lit up as the flavors of the small yellow ground cherry fruit exploded on my taste buds. Notes of pineapple, strawberries, tomatoes, and tropical tang ensued.

The Tyrant — never one to miss out on an exciting food experience — soon followed, and we were both equally thrilled.

Numerous questions followed: What evil conspiracy had caused us to never hear of ground cherries before? Why weren’t ground cherries in every summer farmers market and grocery store? What other amazingly delicious heirloom plants were hiding in similar obscurity?

Our ground cherry experience in Eliza’s summer garden had a profound impact on shaping our life’s trajectory. When you taste your first golden-ripe ground cherry, we hope it will also have an equally profound impact on your love of plants and home-grown organic food.

Hopefully, this article will expedite your journey towards your first date with ground cherries…

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I. An introduction to Physalis plants & ground cherries 

Perhaps because they’re rare today, there’s a lot of confusion in online articles we read about ground cherries and the genus Physalis (husked fruit in the nightshade family). You can tell pretty quickly that many of the folks writing about these plants have never actually grown them, and are instead getting their information from other people who have written about the plants without actually growing them.

One source of confusion we often see is people mixing up different species of Physalis fruit, since the plants sometimes have the same common name depending on where you live.

The four distinct types of Physalis fruit we’ve grown (all of which we’ve seen called “ground cherries”) are: P. pruinosa, P. peruviana, P. alkekengi, and P. philadelphica / ixocarpa. Quick distinguishing notes on each of these species below: 

1. Strawberry ground cherry, ground cherry, or husk cherry (Physalis pruinosa)

Physalis pruinosa has many common names including

• strawberry ground cherry,
• ground cherry, and 
• husk cherry

…among others. For simplicity’s sake, when we say “ground cherry” in this article, we’re specifically referring to Physalis pruinosa.

We’ve grown ground cherries for a decade in our garden, and I’ve grown them commercially for local restaurants as well. Ground cherries are native to Mexico and the southern United States. They’re annual, heat-loving plants that die in late summer (in our zone, 7b) after they’re done producing hundreds of ground cherry fruits.

As mentioned in the introduction to this article, ground cherry fruit tastes like a combination of pineapple, strawberries, tomatoes, and tropical tang.

• plant dimensions: 2′ H x 3′ W
• production: 2-5 pounds of fruit per plant
• growing conditions: ground cherries tolerate poor soil and neglect much better than other summer garden plants, but will produce best with full sun, rich soil, and irrigation.

2. Incan golden berry or Cape gooseberry (Physalis peruviana)

Sometimes also called ground cherries, we call Physalis peruviana by the common names ‘Incan Golden Berries’ or ‘Cape gooseberries’. This plant is believed to be native to South America (modern day Peru), perhaps the result of breeding work by the Incans.

It’s flavor is extraordinary, and much different than ground cherries (Physalis pruinosa). It’s similar in flavor to a tangerine with notes of pineapple.

Incan golden berry fruit are slightly larger than a ground cherry. The plant is a perennial in our zone if winter temps don’t go below 15°F, but it takes at least a month longer to begin producing fruit than ground cherries. The fruit is also much more attractive to certain pest insects than ground cherries, so yields are smaller.

• plant dimensions: 5′ H x 4′ W
• production: 1 pound of fruit per plant per year (in warmer climate zones and/or with better pest control measure, fruit production would likely be much higher)
• growing conditions: similar to tomato: full sun, rich soil, and irrigation.

3. Chinese lantern (Physalis alkekengi)

Chinese lanterns are absolutely beautiful plants that are usually grown for ornamental purposes due to their bright red husks. The Tyrant and I have made a few half-hearted attempts at growing them, and achieved half-hearted results. 

The biggest problem in the past? Flea beetles are drawn to the young plants like magnets, and we don’t tend to baby our plants.

Chinese lanterns are perennials in mild-warm climate zones. There is some debate as to the fruit’s edibility (there is a consensus NOT to eat them unless they’re completely ripe). However, the plant (including leaves and roots) is sold and used as a medicinal herb in Asia where it’s native.

Having eaten the ripe Chinese lantern fruit several times with no ill effects, my continued existence attests to the fact that it is indeed edible at least to me and at least in small quantities. However, the flavor was extremely sour, so the ripe fruit is probably best cooked and sweetened.

• plant dimensions: 5′ H x 4′ W
• production: 1 pound of fruit per plant per year
• growing conditions: full sun, rich soil, and irrigation (use organic insecticide on seedlings to kill flea beetles)

4. Tomatillo (Physalis philadelphica and Physalis ixocarpa)

Our second favorite Physalis fruit after ground cherries are tomatillos, due to their high productivity and how easy they are to of grow. Tomatillos are hugely popular in Central and South America, and Latin American cuisine is hugely popular in our kitchen.

There are large and small-fruited tomatillo varieties. There are also purple and green varieties. All offer an excellent, tangy-sweet flavor and all grow as annuals in our climate zone. When I’ve grown tomatillos for restaurants, I much prefer the giant green tomatillos which are much more economical to produce on a price per pound basis.

• plant dimensions: as large as indeterminate tomatoes, 6-7′ H x 3′ W
• production: 10-15 pounds of fruit per plant
• growing conditions: full sun, rich soil, and irrigation

II. How to grow and use ground cherries

Now that you know the difference between the various species of Physalis fruit commonly called ground cherries, let’s dive into how to grow actual ground cherry plants and use ground cherry fruit (Physalis pruinosa). 

One of the many virtues of ground cherries is that they’re easy to grow organically relative to most other summer garden plants.

Here’s how you can grow your own ground cherries from seed:

Step 1: Start ground cherries from seed

a. When to start ground cherry seeds:

Start your ground cherry seeds indoors in cells 6-8 weeks before your last frost date (find your frost dates here).

There are plenty of places to buy certified organic ground cherry seeds online. (Here’s a source for a great variety we’ve grown named Aunt Molly’s ground cherry.)

b. What to start ground cherry seeds in:

Be sure to start your ground cherry seeds in organic seed starting mix (like Espoma’s), not potting soil. Potting soil usually has larger chunks that aren’t ideal for small seeds and seedlings.

Either use reusable plastic cells, biodegradable pots, or Ladbrooke soil blocks. Ground cherries aren’t very sensitive to root disturbance, so they don’t suffer transplant shock like some other seedlings do.

c. Sowing depth and care for ground cherry seeds:

• Sow seeds 1/4″ deep.
• Ground cherries are heat-loving plants. The seeds will germinate best at temperatures between 75-85°F, so a seed heating mat will yield better, faster seed germination.
• Keep the seed starting mix damp, but not wet, to help ensure good seed germination.

Step 2: Grow healthy ground cherry seedlings

a. Ground cherry plants’ light & temperature requirements 

After sprouting, your ground cherry seedlings/plants will need a minimum of 6-8 hours of direct light.

If outdoor temps are over 60°F, you can put them outdoors. When temps are below 60°F, it’s very helpful to have a DIY indoor grow light system to keep your seedlings happy and healthy.

b. Ground cherry plant nutrition/fertilizer requirements. 

Quality seed starting mixes contain nutrients and beneficial microbes necessary to keep your seedlings happy and healthy – at least for several weeks.

If you notice slowing growth and/or yellowing leaves on your ground cherry seedlings, you’ll want to give them a boost of nutrition. We recommend using an emulsified organic liquid fertilizer like fish emulsion. 

Carefully follow fertilizer dilution ratios on whatever fertilizer you use because over-fertilizing your seedlings can kill them as well.

c. Indoor pests on ground cherry plants/seedlings

When growing indoors, you might encounter two potential pest insects that can harm your ground cherry seedlings:

i. Aphids are tiny sap-sucking insects that multiply rapidly. Left unchecked, they can quickly multiply to the point that they kill your plants. (Outdoors, predatory insects usually keep aphid populations in check.)

If you have an aphid problem, use organic neem oil spray, which suffocates the aphids. Neem oil is so safe, that it’s also sold as a hair care and skin lotion for human beings.

ii. Fungus gnats are tiny flies that look similar to fruit flies. The adult flies are harmless to your plants, but their larvae eat the roots, weakening or killing the ground cherry plants.

If you see the adult flies hovering around your plants, that means they’re mating and laying eggs in your seedling soil. If they proliferate, they’ll eat the roots of your seedlings to the point that the plant dies.

A few years back, we had a particularly bad fungus gnat infestation in our seedlings. We applied predatory nematodes to our seedling soil and a week later, no more fungus gnats.

d. “Hardening off” your ground cherry plants

Keep in mind that seedlings (including ground cherries) that have only been exposed to artificial light risk getting severely sunburned with extended exposure to outdoor sunlight for the first time – especially with intense spring & summer light.

That’s why you’ll either want to regularly expose your seedlings to sunlight as they grow OR “harden them off” before transplanting them outdoors. “Hardening off” simply means following a graduated sunlight exposure schedule such as:

• Days 1 – 3: Place your ground cherry seedlings outdoors in a shady spot that will only get 3-5 hours of direct sunlight throughout the day.
• Days 4 – 5: Place them in a slightly sunnier spot that will get 5-6 hours of direct sunlight.
• Days 6 – 7: Place them in a full sun spot.

Step 3: Transplant and grow ground cherries 

After ~6 weeks and once they’ve been hardened off to outdoors sunlight, it’s time to transplant your ground cherry plants outdoors.

Ground cherries are closely related to tomatoes (another nightshade). Both plants have “adventitious roots,” meaning the tiny hairs on the stems will actually form new roots when they come in contact with soil. Slightly burying the stems during transplanting will help them develop a more robust root system.

If you plant your ground cherry seedlings in good compost or worm castings, they won’t require any extra fertilizer – in fact, they actually perform relatively well even in poor soils.

After transplanting, we apply about 3″ of mulch (wood chips or chopped leaves) to the soil surface around our ground cherry plants to help maintain biological soil fertility, soil moisture, and ideal soil temperatures.

Mulching also makes it much easier to gather clean ground cherries at harvest time, rather than ground cherries covered in dirt.

Do you have to plant more than one ground cherry plant to get fruit? 

Ground cherries have perfect flowers and easily self-pollinate when their flowers are shaken by a pollinator or wind. If you only have a small amount of space, you can plant a single ground cherry plant and still get fruit.

Ground cherry pests 

In our experience, if you keep your ground cherry plants happy & healthy (good soil, adequate irrigation, full sun), they’ll outgrow and outlive any pest insect, from white flies to flea beetles. Our ground cherry leaves often end up with quite a few tiny flea beetle holes in their leaves, but plants’ physiological response to pest insect exposure can actually lead to a boost in their nutritional composition (more nutrient-dense foods for people).

If you’re a seed saver, note that pest exposure in one generation also helps future plant generations epigenetically adapt to those specific pests, making for hardier plants adapted to your specific bioregion.

Step 4: Harvest ground cherry fruit 

Ground cherry fruits basically harvest themselves.

How do you know when ground cherries are ripe? The husk turns brown and the fruit drops on the ground. The ripe fruit inside the husk should be golden yellow in color when ripe.

To harvest ground cherries, give the bush a very gentle shake. During peak ground cherry season, this will create the delightful sound of dozens of ground cherries cascading to the ground. Simply peel off the papery ground cherry husk and enjoy!

Ground cherry fruit left on the ground to rot will readily reseed, becoming next year’s plants. We encourage you to save the largest fruit from your healthiest ground cherry plants to start breeding your own ground cherries.

Ground cherry eating/flavor tip:

Let your freshly picked ground cherries sit 24-48 hours indoors in their husks before eating them. The flavor sweetens and intensifies significantly over this time period with notes of caramel developing. 

How long will a ripe ground cherry fruit last? 

Stored indoors out of the sunlight, ground cherries can last for 2-3 weeks. For maximum storage life, leave the protective husks on the fruit until you’re ready to eat them. 

Ground cherry fruit are still edible after a few weeks, but they start to become dehydrated. There isn’t any shame in eating ground cherry “raisins,” which are quite delicious. 

Can you refrigerate ground cherries?

Unlike tomatoes, you can refrigerate ground cherry fruit for storage. Put them in a ziplock bag in your produce drawer and they’ll last for weeks. 

How do you use ground cherries? What are they good for? 

If you have more ground cherries than you can possibly eat fresh, count yourself lucky.

Pies, preserves, breads, fruit leather… there’s infinite numbers of ways you can use ground cherries. We’ve heard of ground cherry pies selling for $20/each at a local farmers market.

Some of our favorite ground cherry recipes are:

1. Ground cherry preserves with vanilla and brandy

2. Panna cotta with ground cherry bourbon sauce

3. Gluten-free ground cherry crumble with oats and pecans

III. Frequently asked questions about ground cherries (Physalis pruinosa)  

Are tomatillos the same as ground cherries? Are cape gooseberries the same as ground cherries? Are ground cherries the same as Chinese lanterns?

No. These are all different but related fruits in the Physalis family. Please reference the breakdown between species in Section 1 of this article.

Is a ground cherry a fruit or vegetable?

Ground cherries are a fruit… technically a berry if you want to be particular about things.

Will ground cherries ripen off the plant?

Not well. Green ground cherries aren’t very tasty and it’s generally not a good idea to eat unripened nightshade fruit.

If they’re far enough along in maturity, green ground cherries will ripen, but won’t develop as good a flavor. It’s best to only pick ripe ground cherries with brown husks that have fallen off the plant on their own.

Are all ground cherries edible?

There are lots of plants in the Physalis family that might be called “ground cherries.” See section 1 of this article for edibility of specific varieties.

Are ground cherries/physalis good for you?

Yes. Whole, organically grown fruits and veggies are good for you in general. Since they’re a rare fruit, ground cherries (Physalis pruinosa) don’t have a standardized USDA nutritional analysis.

However, independent researchers have found them to be high in fiber, protein, plus a wide array of vitamins, minerals, and amino acids. Plus, eating ground cherries makes you smile, and smiling is good for you too.

Can dogs eat ground cherries?

We can attest to the fact that other mammals — namely chipmunks and squirrels — love ground cherries. However, it sounds like ground cherries might not be good for dogs, so it’s best to take precautions (such as fencing) to keep your dogs out of your ground cherry plants.

Can you freeze ground cherries?

Yes, you can freeze ground cherries. After freezing, they’ll be suitable for cooked recipes, not for fresh eating.

Are ground cherries self-pollinating?

Ground cherry flowers are like tomato flowers in that they have both male and female reproductive organs and are self-fertile. All that’s required for pollination is a gentle breeze or an insect to shake the flower.

Are ground cherries and husk cherries the same thing? 

Common names of plants can vary from region to region or even person to person. However, ground cherries and husk cherries are usually the common name given to the same plant, scientific name Physalis pruinosa. 

Can you grow ground cherries in pots?

Ground cherries grow perfectly well in pots (we grow a few every summer in pots on our back porch). Grow them just as you would a pepper or dwarf tomato plant:

• good organic potting soil,
• at least 1 gallon pot per plant, and
• maintain soil moisture levels.

Sub-irrigated planters (SIPs) are a great solution.

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We hope you’ll enjoy eating golden ripe ground cherries in your summer garden for many years to come!

 

 

KIGI,