There is a growing trend to embrace the unusual when it comes to fall pumpkins.

Colors such as white, gray and green depart from the “normal” orange, and miniature sizes and flattened shapes are highly sought after.

Pumpkins sporting warts and bumps are another hot trend.

But are warts on pumpkins desirable? Here are some reasons for warts on pumpkins.

Viruses: Some warts are due to mosaic viruses which can also cause mottled coloration and stunted growth.

Aphids are usually the culprit for transmitting mosaic viruses in pumpkins.

Although mosaic viruses mean the fruit will be smaller and unusual looking, they don’t affect the shelf life or edibility of mature pumpkins.

Edema: Edema is an accumulation of water within the pumpkin caused by wet and cool weather conditions.

Excess water creates enlarged cells that burst, causing the tissue to heal and create an enlarged, corky area on the skin.

Edema usually affects the part of the pumpkin lying on the ground.

Warm and dry conditions will mitigate edema, but the warts on the skin will persist.

Bacteria: Pseudomonas syringae is a bacterial pathogen that creates wounds in the skin of pumpkins.

Under the best circumstances, this bacterium causes warty scabs, giving the pumpkin character.

But these scabs can burst, allowing additional pathogens to enter, causing the crop to rot.

Insects. Insects, such as cucumber beetles, may feed on the skin of developing pumpkins, leaving wounds that heal as bumps and scars.

Warty Heirloom Pumpkins: The most important answer to what causes warts on pumpkins lies in pumpkins themselves.

Before they were bred to be smooth symmetrical canvases for Jack-o’-lanterns, pumpkins had natural bumps and indentations.

These tendencies led to heirloom varieties that are predecessors of today’s hybrid curiosities.

Gardeners can easily find the seeds of these heirlooms for sale and grow them at home.

“Galeux d’Eysines”: The variety name of this Cucurbit maxima translates to “scabby from Eysines.” A more appealing name is “peanut pumpkin” because the abundant, crusty bumps on the skin resemble peanut shells.

It is not stringy and is recommended for soups and stews.

“Marina di Chioggia”: Another variety of Cucurbit maxima, “Marina di Chioggia” is a flattened turban shape with pronounced bumpy ridges.

Though dark green when mature, the flesh is a pleasant golden-orange and is excellent when used in Italian dishes such as stuffing ravioli or making gnocchi.

“Musquee de Maroc”: Also call Moroccan musk squash, this variety of Cucurbit moschata has a classic pumpkin shape and ribs, punctuated with pronounced clusters of green-orange knobs.

It is resistant to drought and squash bugs and has a melon-like flavor.

Super Freak Pumpkins: Siegers Seed Company developed this series of warty pumpkins. (Strokes Seed now owns Siegers Seed Company.)

Many rounds of selective crossbreeding created these hybrids.

The hybrids belong to the Cucurbit pepo species, the same species as the traditional Jack-o’-lantern.

Some names of these pumpkins are: “Baby Bumps,” “Goose Bumps,” “Goose Bumps II,” “Grizzly Bear,” “Knuckle Head” and “Scarface.”

Gourds in this series are “Gremlins” and “Goonies.”

If you are looking for the ideal warty pumpkin to grow, consider your goal, which may be just eye-catching or their true strength, which lies in their long-valued flavor and culinary versatility.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613 \