Sweet Potato Pest, the Weevil

 I knew that my sweet potatoes were infested with something, but I assumed it was wireworm. The blackened tunnels snaking through many of my sweet potatoes looked similar to those I had seen years ago at one of my volunteer projects, a Plant a Row for the Hungry garden.

However, today, as I was poking through my basket of sweet potatoes, looking for a "good one" to cook for lunch, a critter crawled out of one of the sweets. Here he/she is:

A little blurry, because it was moving, but the critter is definitely a weevil.

A weevil!

Note -- there is another weevil on the right side of the tuber that is not moving, because I smashed it -- a reflex action -- before I remembered that I needed to take a picture, to share with my gardening friends!

Damage caused by sweet potato weevils

My sweet potatoes that have black tunnels inside also have holes in the outer skin, where the pests have gone in and out of the tubers. 

This is the inside of the tuber that the full-grown weevils crawled out of:

Weevil damage in my sweet potatoes

I sliced away a bit of the side on that left-hand piece, to show the snaking tunnels more clearly. 

What I didn't realize back in the summer is that holes in the leaves, that I saw at that time, could have been caused by weevils. Honestly, the thought that weevils might be responsible for holes in the leaves didn't even enter my mind. This is a new pest for me!

Pest-predators in the garden, like this frog, could not keep up with the hole-making critters.

What makes figuring out which pest ate holes in the leaves difficult is that many pests, sweet potato weevils included, mostly eat at night, when I am not likely to see them. 

It also is new to me that a leaf-eating pest could also be a tuber-eating pest. My experience is that the two groups are usually completely separate. 

The pictures in University of Florida's "Featured Creatures" article on sweet potato weevils are pretty horrifying. They show a tuber with an entirely blackened interior spotted with maggoty-larvae. For the non-squeamish, there are close-up pictures of the larvae, to aid in identification.

Getting rid of sweet potato weevils

The weevils are unlikely to just disappear without some kind of "help". Since I am an organic gardener, the kinds of "help" I can give, to remove the weevils from my garden, are limited.

However, I am hopeful. The UF article linked above does include multiple actions that organic gardeners can take to reduce or eliminate a sweet potato weevil infestation. These are suggestions that UF offers:

Get rid of other plants in the morning glory family

Sweet potatoes are in the morning glory family, and the sweet potato weevils feed on all related plants, apparently. Unfortunately, I live within a half mile of the beach, which is home to a lot of beach morning glory vines. Those are not mine to remove (and I wouldn't want to, because they support a lot of pollinators).

I also have some morning glory vines climbing one of my clothesline supports. This is going to change.  

I will be looking for another flowering vine to replace those morning glories, and I will pull up all the new morning glory vines that sprout in that area in spring.

Keep the soil moist

Dry soil opens up as it cracks, which makes it easy for the weevils get into the ground to infest sweet potato tubers. Last year (2022) was very dry here, but I did not worry much about keeping the sweet potatoes watered, because they are so drought tolerant. Even though the garden is mostly sand, cracks probably formed.

Moist soil also helps promote growth of a fungus that fights the weevils underground.

The previous year had been super-wet. We ended up with more than 100 inches of rain in 2021. If the weevils were already in the garden back then, the constant wetness (no cracks, plus happy fungus) may have kept them from doing obvious damage.

Rotate crops

Always, gardeners are told to rotate crops -- making sure that no crop is grown in the same spot within three to five years. For home gardeners, this is mostly not practical, or even possible. All we can do is try, and be hopeful. 

However, for many pests, including sweet potato weevils, this recommendation might not be super-useful.

Clean up old vines and tubers

Removing every bit of vine and tuber from the garden at harvest time removes food that weevils might survive on over the winter. 

However, cleaning up every single bit of vine and tuber is difficult.  No matter how many times I re-dig an area, it seems like I always find one more small tuber or length of vine. Still, I will hunt for leftover bits of vine with even more diligence as I prepare the garden for spring planting.

If I had known about the weevils in fall, when I harvested the crop, I would have put all the vines into the landfill instead of my compost pile. There are probably some weevils humming happily in my compost as I type, waiting for me to spread them back onto the garden. 

Luckily, there is another option for getting rid of weevils that will make my oversight ok.

Add some parasites

This is where I am headed. There are wasp and ant predators on sweet potato weevils that may already be working in my yard, but beneficial nematodes seem to offer the best hope for reducing the weevil population by a significant amount.

Calling them beneficial nematodes makes them sound totally wimpy, but these little guys act as parasites on pests, finding a way inside, injecting bacteria that kill the pest, then "eating" the remains of the dead pest. 

Even better, beneficial nematodes do not harm frogs, birds, salamanders, squirrels, or other garden (or nearby) wildlife, unlike many chemical control options.

I had already been looking at nematodes as a treatment for wireworm -- when I thought that was the cause of my sweet potato damage -- and also for small hive beetles, for my beehives. 

Back in north Georgia, treating the Plant a Row for the Hungry garden with beneficial nematodes worked like a miracle to get rid of the wireworms. It took two years before the wireworms were completely managed, but the first crop after applying the beneficial nematodes showed BY FAR less damage than the previous year's crop.

I am looking at a "Combo Pack" of beneficial nematodes from Arbico Organics. This is a pricey option, but I am expecting it to be totally worthwhile.

Beneficial nematodes in both products are listed as attacking sweet potato weevils. Applying both seems like a good option for making sure that the weevils get attacked. The smallest combo pack covers a lot of ground, so I will also apply it around my fruit trees and other places in the yard.

The nematodes need to be applied after the garden has warmed up a bit, and they have a super-short shelf-life, so it will be a few weeks before I order these. 

I will let you know how this all goes! At sweet potato harvest time, I will have some kind of result to share.

Choosing Between Determinate and Indeterminate Tomato Varieties

 Garden-planning time is underway! Seed catalogs have been arriving for a few weeks, and gardeners are reading descriptions for the hundreds of amazing tomato varieties available and trying to decide which ones to grow this year.

'German Gold' tomato

Among the many features that we ought to consider, along with disease resistance, heat tolerance, and whether we want canning tomatoes or fresh-eating tomatoes or both, is the growth type. Do we want determinate or indeterminate plants?

Understanding the differences in how determinate and indeterminate tomato plants grow and set fruit can help us choose the best type for our home garden. The differences can influence not only which type we choose, but also how the plants should be spaced, trellised, and pruned.

Difference between growth types

Plant size at maturity

The first difference that we can easily see in the garden is how tall the mature plants become.

Determinate tomato plants usually grow between one and  five feet in height, which means they are less likely to overwhelm a small garden. Many patio and container type tomatoes have a determinate growth habit.

Indeterminate tomato plants can grow to become much taller, as much as 8 or more feet tall. Main stems of plants in this growth type continue to grow in length/height for as long as they are healthy and the weather does not turn to freezing. Many heirloom tomato varieties are indeterminate types.

Semi-determinate tomato plants are a third growth type that you may see. As you might have guessed, the characteristics of semi-determinate plants are in between those of the other two types. These plants are a little less tall and rangy than indeterminate type tomatoes, but not as compact as determinate types. This growth type can work well in a small garden.

Differences in when they set fruit

Timing of tomato fruit production and ripening -- when the fruits are ready for harvest -- is another difference between the growth types that we can see in the garden.

Determinate type tomato plants set almost all of their fruit within a few weeks, and then their productivity slows way down. The fruits form on side-branches that are fairly closely spaced on the plants.

Indeterminate type tomato plants produce fruit all summer and into the fall, if they stay healthy. The fruits usually are spaced farther apart on indeterminate plants that they are on determinate plants.

Semi-determinate type tomato plants can produce fruit through the whole season, but they may not be as productive toward fall as an indeterminate type.

Trellising the types of tomatoes

Tomatoes need to be held upright, one way or another, to keep the fruit off the ground. The fruits are more likely to rot or attract small animal pests if they touch the ground.

Staking tomato plants

Up North, many gardeners prune and tie an indeterminate tomato plant to a single stake. In the South, I have seen that practice result in fruits ruined by sun-scald. In general, the Southeastern states have too much heat for too long for staking tomatoes to be a viable option.

However, I did see a remarkably productive patch of staked tomatoes in Florence, Italy, when I was lucky enough to visit there, that looked healthy and showed no scalded fruit. Summer is hot in Florence, but it is also dry, unlike the very humid summers of the Southeast. 

The close spacing in this tomato patch, in the image below, may not be as successful here, where tomato leaf diseases promoted by the high humidity can destroy our plants in a short span of time. I am thinking about trying a small patch of staked tomatoes this year, as an experiment.

Raised bed full of staked tomato plants in Florence, Italy

Caged tomato plants

Mostly, home gardeners in the Southeast rely on tomato cages to support their tomato plants, for all growth types. I learned at a Georgia Organics conference, several years back, that caged plants produce more tomatoes per plant than trellised or staked tomatoes. This makes caging a great option for small gardens.

Determinate tomato plants, since they stay smaller, can be supported by less robust structures than indeterminate plants. The indeterminate growth types need strong, tall structures.

Most garden centers do not sell sturdy enough cages or supports for indeterminate tomatoes. One option is to make your own out of strong hog fence or other sturdy wire mesh. Find a mesh that has its wires about 6-inches apart, and create a cylinder that is about 18-20 inches across (diameter). 

The wire cylinder makes a good cage/support for tomato plants, but it will need to be held upright with stout posts, to keep it from blowing over in a big wind or being toppled by the heavy top-growth of an especially robust tomato plant.

Another caging option is a product called a Texas Tomato Cage. These strong, and collapsable (for easy storage!), tomato cages are awesome -- I use them -- but they are pricey.

Pruning the different types of tomato plants

Another great aspect of caging a tomato plant, instead of trellising or staking, is that it reduces the amount of pruning needed. Texas A & M Extension goes so far as to say this about pruning tomatoes: "Suckering or pruning the plants is not necessary when you use cages."

If you feel the need to prune, thin the number of main stems of indeterminate plants to just three or four, early in their growth, then leave them alone.

For determinate plants, any pruning should be very early in the plant's life, just enough to guide its growth. Pruning this growth type can result in lower production of tomatoes.

The Texas A&M article linked above also adds this about pruning determinate tomatoes: "Do not prune plants of determinate hybrids if you plant to trellis and support them with twine woven around wooden stakes."

Which type is best for my garden, determinate or indeterminate?

The different growth habits have benefits and drawbacks. here are some things to think about as you plan your garden:

Characteristics of determinate tomato plants

• Ripen most of their fruit in a short time-frame -- this is great if you plan to do some canning, where having a lot of ripe tomatoes all at once is helpful.
• Shorter productive lifespan means that there will be space in the garden in late summer for other crops. This can be good if you are short on space but want more variety from your garden.
• Shorter productive lifespan also means that gardens that are troubled by a lot of late-summer tomato plant diseases have an improved chance to harvest plenty of tomatoes before the diseases destroy the plants.
• Smaller-growing determinate types can fit in small gardens that might not contain an indeterminate type. You can plan to have another determinate type plant ready to replace the first one, when it quits making abundant tomatoes. You can have a second harvest in the fall!

Characteristics of indeterminate tomato plants

• Produce over the whole summer, as long as they stay healthy. This is great if you like to have a few tomatoes to eat every week.
• Long-time in the garden means these plants are exposed to more plant diseases and pests for a longer time than determinate plants. Relying on disease resistant varieties becomes increasingly important.
• Many heirloom varieties are indeterminate, and the heirlooms offer a wide range of flavors that is hard to find in determinate types.
• These can grow to be quite large. Read the variety information carefully. One year, I grew a 'Matt's Wild Cherry' that erupted out the top of its cage and sprawled across 10 feet of garden. Do you have room for that?

'Wuhib' is a semi-determinate paste-type tomato that did great in my old North Georgia garden

Examples of determinate and indeterminate tomato varieties

Back in North Georgia, many gardeners that I knew were dedicated to particular varieties. Some always grew 'Celebrity', some planted dozens of 'Park's Whopper' every year, and some were 'Better Boy' loyalists. 

I am still learning about varieties that are best for the Mississippi Gulf Coast, but so far, the same varieties I've grown from this list are still proving to be successes.

Some determinate tomato varieties with good disease resistance for the South:

• Celebrity (hybrid)
• Dixie Red (Hybrid)
• Mountain fresh (hybrid)
• Patio Choice Yellow
• Homestead 24 (old, open pollinated, but not heirloom) may be semi-determinate
• Long Keeper (heirloom, I think) a storage tomato
• Rutgers (old, open pollinated, but not heirloom) may be semi-determinate

Some indeterminate tomato varieties with good disease resistance for the South:

• Park's Whopper (hybrid)
• Better Boy (hybrid)
• Cherokee Purple (heirloom)
• Sweet 100 (hybrid) cherry tomato
• Mortgage Lifter (heirloom)
• Arkansas Traveler (old, open pollinated, but not heirloom)
• Black Krim (heirloom)

Making your final tomato variety selection 

Did I already say the part about reading variety descriptions carefully as you choose your tomato plants? This works best if you are growing from seeds, since the catalogs give more detail than plant-tags in a garden center. But, checking varieties online, on your phone, as you face the racks of plants in a garden center can be helpful.

The descriptions contain clues about whether a variety is a good match for your garden. For example, if you live in the Southeast, and a tomato variety description says that it produces well in dry conditions, the variety might not be a great match for the rainy, humid Southeast.

Also, consider this: my copy of the 2023 seed catalog from Southern Exposure Seed Exchange says that its 'Cherokee Purple' tomato plants stay shorter than the 'Cherokee Purple' plants grown from seeds of some other suppliers.  This statement presents a topic worth understanding.

The same variety offered by different suppliers might not be the exact same plant. If you have grown a variety from one seed supplier, and it did great in your yard, be aware that seeds of the same variety from a different supplier might not give the same results. 

The plants may be generally the same, but different in key particulars.

I have known a lifetime-gardener who grew 'White Mountain Half Runner' beans for decades, but she would only buy from one supplier -- Morse (now Ferry Morse). She said that the same variety from other suppliers did not actually produce the same beans, in flavor, abundance, and growth habit.

So, when you find a tomato variety that you love, that meet the needs of your household, and that does well in your yard, remember (or write down) the name of the seed or plant supplier.

After the Freeze

 The pre-Christmas freeze did not do too much damage in my yard. The parts of the garden that weren't covered looked pretty rough, and I've had to trim away dead leaves from the collards and kale, but all of the covered plants look mostly ok.

Cold-burn on leaves of two of my broccoli plants

However, one of my brothers sent me a picture of damage to his veggie garden.

His broccoli plants must have totally frozen, despite being covered to protect them, because after the thaw, they basically liquified. I am sure that cleaning up the soggy mess was not fun.

My gardening brother is in South Texas, and his garden did not get much colder than mine, maybe a degree or two. I do know, though, that I used pretty much every bit of lightweight fabric in the house out in the yard over those four freezing days.

Covering my Southern Garden in a Freeze

So sorry that I did not document this in photos, but what follows is how I covered my garden beds:

• Pushed wood stakes into the beds, with upside-down flower pots on the tops, to keep the covering material from weighing down on the plants
• Used sheets -- yes, the ones that normally go on beds in the house -- draped over the garden beds
• Covered the sheet layer with thin plastic sheeting
• Pinned the edges of both layers down to the ground with anything I could find -- rocks, bricks, logs, boards. The coverings had to withstand 30 mph winds, so the weights needed to be heavy.

After the freeze was over, I had a lot of laundry to do. All of those sheets needed to be washed, and I do not have a clothes dryer. It took a couple of days to get everything washed and then dried out on my clothesline!

A lot of moisture condensed onto the plastic sheeting, which meant it all needed to be dried, too. The huge plastic sheeting looked pretty odd out on the clothesline, but it did get dry.

All of that effort was totally worthwhile. The garden bed pictured below shows very little cold damage. The Bok Choy sent up flowers immediately, which is slightly annoying, but everything else just shows a little cold damage on some of the leaves. 

Garden bed with broccoli, carrots, cabbages, and more.

Cold damage on most of the covered plants looks like bleached areas on the leaves. Mostly, those bleached areas are where the sheets touched the plants.

Elsewhere in the garden, the radicchio, lettuces, escaroles and endives, arugula, sugar snap peas, and other plants under the double layer of sheets (fabric plus plastic) look unfazed by the freezing weather.

Winter is not over; odds are good that more freezing weather will arrive over the next couple of months. 

Professionals use heavy-weight row covers to protect their crops, but not all gardeners have them on hand. At my house, we tend to improvise to use the resources that are already here. Thus, the sheets.

Hope that your gardens are all recovering nicely and providing good food for your families!

-Amy

Welcome to this Garden Blog

 Welcome!

Sharing information about growing good food is important to me, so that is mostly what will be on this website.  I have been growing food for decades, and I have made plenty of mistakes, but I also have found a lot of joy and personal satisfaction in bringing food from our yard into the kitchen.

This new website is part of an ongoing writing project.  It is the third blog that I have started with food-gardening as a focus. 

The first blog was called Atlanta Veggies, and it is still available online because it is a "blogspot" site, like this one. The second blog, also with the name Small Garden News, was on Wordpress, and it disappeared from the internet when I quit paying for it to be there. 

However, my food-gardening continues!

My Mississippi Garden

 We moved to the Mississippi Gulf Coast, from metro-Atlanta, in the early spring of 2020. I went from gardening in red clay to gardening on a sand dune. 

The switch has been a bit of a shock, but this past year has been mostly productive. It was a tough year in terms of the super-abundant stink bugs and a serious lack of rain, but we still have brought plenty of food in from the yard.

In advance of the recent pre-Christmas freeze, we harvested a pile of food from the garden, in case all the plants died in the cold:

The photo above shows kumquats, a tub full of mini salad greens, arugula, a little marjoram, a lone green tomato, cilantro, mustard greens, broccoli, assorted radishes, turmeric, and ginger.

Happily, a surprisingly large part of the garden survived four days in a row of temperatures that dropped to the low-to-mid-twenties. There is still plenty of food growing, for us to enjoy in the coming weeks.

Thanks for stopping by!  -Amy at Small Garden News