Pawpaw

Berries, birds, and cicadas in 2021

Maryland Grows3 Comments

For me, at least, it’s been a bumper year for berries.

Black raspberries in my garden in mid-June

In some years, I harvest only sparsely from the various fruit plantings in my landscape. Black raspberries, in particular, get snatched by birds before I can get to them. Not this year. I had them all to myself until this week, and they’re now pretty much done anyway. My guess—and I haven’t seen any science to back this up, but it makes sense—is that the birds have been too busy scarfing down cicadas to bother with berries. Now that the cicadas are gone, they may turn their attention to my fruit-bearing bushes, but I’ve had a head start.

Periodical cicadas are not an unqualified blessing for fruit growers, of course. Female cicadas lay their eggs in branches of a certain diameter, which are abundant on a lot of fruiting plants. This can cause dieback at the ends of these branches. The affected branch tips will fall off naturally over time; you can prune them if they bother you, but remember that cicada eggs are inside slits in the branches, and won’t hatch until probably August. I’m just going to leave mine alone.

Below you can see dieback on blueberry and pawpaw plants caused by cicada laying.

I didn’t bother covering most of my fruit plants, but here in Germantown we didn’t have a huge number of cicadas, either, so the damage has been minimal and the plants will recover. Some growers used netting to keep the bugs out, which is of course really inconvenient if the plants fruit during the same period. I was startled a number of times while harvesting when I moved a branch and suddenly encountered staring red eyes. The cicadas found my blueberries early on, as you can see by this nymph exoskeleton still clinging to a berry that ripened underneath it.

But they are not competition for the fruit itself, and since the birds have been ignoring the berries for the most part, my freezer is full of blueberries, black raspberries, and blackcurrants. I’ve made blueberry chutney, blueberry syrup, and blueberry-lavender shrub (from this book). Shrubs are refreshing drinks made from fruit, sugar, and vinegar, ready in a week or less to be enjoyed mixed with sparkling water or in various alcoholic and nonalcoholic blends. I have plans for jam, cassis and other alcoholic infusions, baked goods, and more.

Fruit-bearing shrubs and trees fit into a home landscape very well. Raspberries and blueberries are great starter plants; I also recommend currants for a shadier spot, though you will not be eating them fresh off the plant, so add in some processing time in addition to harvesting time. (Also be sure that you buy varieties resistant to white pine blister rust, for which the currant family is a host.) Pawpaws are wonderful native trees that add dramatic flair to a landscape; you need at least two genetically-different trees for cross-pollination. They will take several years to start bearing, depending on the size of the trees you plant, and mature trees do sucker prolifically, so you will end up with a pawpaw grove that needs some maintenance to keep under control. But the fruit is not commonly available for sale commercially, and it has a great banana-mango flavor that’s unusual in our temperate climate. You can also try blackberries, gooseberries, and figs. All of these are easier to grow in our climate than tree fruits like apples, peaches, and pears, but if you like a challenge, those are possibilities as well. You can find advice on all sorts of fruit growing on the HGIC website.

I’m wondering how next year will go in my fruit-growing adventure. All these cicada-stuffed birds are laying more eggs and raising more youngsters this year, so the population will be higher in 2022, and there won’t be any periodical cicadas to fill their bellies. So I expect I’ll have to be more vigilant about protecting the plants I can protect in order to have much of a harvest. But I’ll probably still have some leftover blueberries in the freezer, and plenty of jars of jam and chutney. Every year is different in gardening, and 2021 will definitely stand out in my memory for noisy cicadas, happy birds, and plentiful berries.

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

Pawpaws: The Tropical Fruit From Our Forests

Maryland Grows6 Comments

Spring is almost here and now we can start thinking about trees to plant if we did not get to that in the fall. Thinking about trees for my garden, I came back to one I have been considering for a while now — one that gives delicious fruit, is native, makes me think of tropical lands, and is not liked by deer! Today’s post is going to be about a little-known tree that’s native to our region, and whose fruits were apparently one of George Washington’s favorites: pawpaws!

What are pawpaws?

Pawpaws are trees that belong to the same plant family as chirimoyas and custard-apples (Annonaceae, the soursoup family; Figure 1). From a botanical perspective, pawpaws are really special because they are the only member of their family adapted to growing outside of the tropics and able to survive our temperate climate.

pawpaw and related fruits
Figure 1 – Pawpaws (left), chirimoyas (top right) and custard apples (bottom right) are all in the same plant family, but pawpaws are the only group adapted to growing in temperate climates.

All pawpaws grow in southeastern North America, but the most common and widespread species is the common pawpaw, Asimina triloba, which is very abundant in our region. The common pawpaw is adapted to growing in well-drained and fertile habitats, such as those found in our forests. I promise you that if you ever walked in a forest in the area, you have seen hundreds of pawpaws growing in groves (Figure 2).

Pawpaw grove
Figure 2 – Pawpaws grow in well-drained fertile soils, and are common in our forests where they often grow in groves. Photo: Katja Schulz.

Why are pawpaws such a “thing”?

Besides being great native trees that grow well in our region, pawpaws have the most delicious fruits. They are considered the largest edible fruits indigenous to the continental United States. The fruits look a bit like a green mango from the outside, but are white/yellow and fleshy in the inside (Figure 3).

pawpaw fruit
Figure 3 – Pawpaw fruits are green on the outside and white and fleshy on the inside. Note the very large seeds. Photo: Elizabeth.

Their flavor is such a delicious one that I always relate it to tropical fruits. People more technical than I am in terms of flavor description say that it is a custard flavor, close to that of bananas, pineapples, and mangos. In any case, believe me when I tell you that these fruits are absolutely delightful and can be eaten fresh, in yoghurts, in cakes, as jams, or frozen in ice-cream!

Why didn’t I know about this before?

That was my very question the first time I tried them! It turns out that producing pawpaws for selling is not super simple. In fact, the fruits are fragile and thus can’t be transported long distances, which reduces their marketability. This means that pawpaws are usually produced and consumed locally. If you do not happen to know somebody with some trees on their land, you probably never got to try them.

Also, the pawpaw fruit season is relatively short (end of the summer), which means that one has to be in the right place at the right time to eat them. In season, pawpaws can be purchased at local farmers’ markets or on farms. You can also try to find them in the forests of the area, where you will be able to smell the sweet aroma of the fruits while you hike or bike. However, be sure to check property rules; harvesting plant materials from park lands is typically prohibited.

Why are you talking about this now? It’s not pawpaw season yet!

That is correct. However, it is pawpaw planting season now, and soon will be pawpaw pollination season, both needed to actually get the delicious fruits in the summer. So, how to plant and pollinate them?

Pawpaws can be grown from seed, but the simplest way to get one for your land is from a nursery. Several nurseries in the area sell pawpaw trees, and your best choices are those which grow trees that are adapted to your local conditions.

Pawpaws are not hard to grow and can be actually cultivated in your own back or front yard! Further, some counties and cities provide financial support to plant these native trees (see for example, Chesapeake Bay Trust and the Maryland Department of Natural Resources).

Pawpaw trees start producing fruit a couple years after planting. However, fruit production is a bit different from that of other fruits you may be growing. In fact, fruits will form only if there is cross-pollination (see this other post), since a pawpaw is not able to properly self-pollinate. This means that pawpaws need pollinators to produce fruit.

pawpaw flower
Figure 4 – Pawpaw flowers have evolved to attract and trick flies and beetles by looking dark and smelling like ripe fruits, the insects’ preferred food and egg-laying site. With this trick, the plant cross-pollinates their flowers without offering any reward to the pollinators. Photo: Judy Gallagher

Pawpaws are pollinated by flies and sometimes beetles, which the flowers attract with their maroon flowers and their ‘yeasty’ aromas (Figure 4). These scents are known to ‘trick’ the pollinators into visiting the flowers, mimicking the odor of ripe fruits that these insects prefer to feed on or lay their eggs. Flowers then attract these pollen dispersers, who, while visiting the flowers, will cross-pollinate them without their will.

You can imagine by now that having more than one pawpaw on your land or in the surroundings of your house will increase fruit production. It will then be more likely that the fooled pollinators will have visited another plant and thus carry pollen when they visit your tree.

Alternatively, if you would like to be absolutely sure to get a good pawpaw crop, you can cross-pollinate them by hand. To do that, get a small brush, pick pollen from the anthers of one flower (check the drawing here to find them), and transfer it to the stigma of another. That way you will get to live your best pollinator life! 😊

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.