I don’t know about you, but insects seem to love my tomato plants. Some seasons the insects aren’t too bad – mainly a few tomato hornworms here and there. Other seasons make me think that a biblical plague has descended upon my garden!
I do try to garden without using insecticides as much as possible, but sometimes I have to throw in the towel and reach for my sprayer. I thought I’d share an “Insecticide 101” post with you. 🙂
Insecticides – What Are They?
It may seem kind of obvious, but these exist to hopefully get rid of the bad bugs (i.e. the ones that want to eat your veggies) and leave the good ones (the ones that pollinate and that eat the bad bugs). They can do it by any of several methods:
- Contact: Some pesticides kill on contact, so when the bugs get sprayed or walk onto it — bye-bye! This generally works on the insect’s nervous system.
- Mechanical: These are the ones that scratch the bug’s outer casing and thereby cause it to dehydrate. This also includes things like sticky traps.
- Ingestion: When the pest comps on the plant where the insecticide is spread, it ingests it. The bug doesn’t die immediately, but rather within a day or two.
- Reproductive: This doesn’t necessarily kill the insect, but rather interrupts the reproductive cycle so that the they can’t multiply.
There are others, but the above are the main categories.
Organic Versus Chemical Pesticides
First, when you get down to it, everything is a chemical. However, for the purpose of this post, “chemical” refers to synthetic chemical pesticides. These are typically created in a lab, as opposed to existing in nature “as is”. Examples are things like DDT, organophosphates, parathion and chlorinated hydrocarbons.
Organic refers to those insecticides that are extracts of naturally occurring ingredients. Examples include pyrethrum, rotenone, neem and Bacillus thuringiensis (Bt).
Very Important: Whether synthetic or organic, by their nature the vast majority of what we consider insecticides/pesticides are toxic, in varying degrees, to people and pets. Always, always, always read and follow the instructions on the label of whatever you purchase.
There are some like diatomaceous earth which are safe to ingest (if you get the food-grade version) and to use around pets, but by and large, treat all insecticides carefully.
I am the first to admit — when it comes to the fire ants that invade my garden, I do use synthetic pesticides — I’ve tried all kinds of organic versions, and they just don’t work. My only defense is to keep the fire ants as far away from my garden as possible, and to use as little synthetic pesticide as possible.
But when it comes to all other pests — my organic insecticides of choice are neem oil and Bt.
One Size Doesn’t Fit All
Unless you only have a specific kind of insect invader, you may need more than one type of pesticide at various points in the gardening season. For example:
- Rotenone is very effective on most types of beetles, but not as much on soft insects like caterpillars and worms. It is quite toxic to fish.
- Neem doesn’t kill directly, but is more of a repellent. It also works to inhibit insect eggs from hatching. Neem is one of the least toxic of the pesticides, but you should still use care when handling it. Interestingly, neem oil can also act as a mild fungicide.
- Pyrethrum is made from chrysanthemums, and it works by attacking the nervous system of insects. It also works as a repellant. It biodegrades quickly and is also among the least toxic to mammals and people – but quite toxic to fish.
- Bt is a bacteria that when ingested by insects, disrupts their digestive tracts. It’s typically used as a spray or a powder, and is most effective on soft-bodied insects — primarily worms and caterpillars that like to feast on your plants.
- Diatomaceous earth works mechanically, by abrading the insect’s exoskeleton. The bug then dies from dehydration. It also works as a flea powder around pets.
These aren’t the only organic insecticides that are out there, but they are the ones that you will come across most often in stores and online.
Which One Should You Use?
You should use what is best for your particular insect problem. You need to know your enemy (which bugs are bugging you), and then choose the insecticide that will be effective against those insects.
Also keep in mind that some insecticides are not made to be used around vegetable plants — they don’t biodegrade well, and you could potentially ingest their residue. Others are safe to use in a vegetable garden, up to the day of harvest. Once again, read the label and follow the instructions — don’t guess!
I hope this has been helpful to you. Now excuse me while I go check my tomatoes to make sure I haven’t had a caterpillar or hornworm invasion and need to get out the Bt!
There’s a lot going on these days with GMO versus non-GMO food. Some say GMO food is fine, some say it’s unhealthy and others don’t have an opinion either way. So what’s the scoop with GMO as it relates to tomatoes?
GMO – A Quick Summary
GMO stands for “Genetically Modified Organism”. It means that an organism has basically been artificially modified in some way, at a genetic level. In looking at Wikipedia, the definition is:
“A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques (i.e. genetically engineered organism).”
By this definition, genes can be moved around in an organism, but no genes from another organism are introduced. However, there is a specific kind of GMO called transgenetic, and it does involve splicing genes from something else. Again per Wikipedia:
“A more specifically defined type of GMO is a “Transgenic Organism”. This is an organism whose genetic makeup has been altered by the addition of genetic material from another, unrelated organism.”
In either case, genes are artificially changed in some way.
What Are Hybrids? Are They GMOs?
Hybrids are crosses between closely related plants or animals. For example, you may want a tomato that tastes like Pink Brandywine, but you want it to ripen much earlier and be only about 2 ounces in weight. To get this, you could cross a Piink Brandywine with an earlier and smaller-sized tomato. The seeds of that cross would have traits from both Pink Brandywine and the other tomato parent. (Note: This is a very simplistic explanation of hybridization; for more information see my post on tomato hybrids.)
Hybrids are not the same as GMOs. For example, you could not cross a Pink Brandywine tomato with a cayenne pepper and get a tomato that is spicy with capsaicin. Tomatoes and peppers are not closely enough related for them to cross with each other and create a hybrid.
You could, however, genetically engineer a tomato to be spicy by introducing a gene for capsaicin production — this would be classified as a GMO.
Are All GMOs Bad?
I don’t know that I can definitively answer that, but personally I would rather stay away from them in my food.
However, here is something to think about. An organism can, spontaneously mutate and change its genetic makeup. Or, if can be bred to display a specific trait, and during the process some other undesirable trait can be expressed.
An example of this is with modern wheat, which has been modified through selective breeding to have more genes than older varieties of wheat. Those extra genes are thought to be responsible for much of the gluten sensitivity that we see in today’s society. No labs were involved, just many years of selective breeding.
And yes, I do try to stay away from wheat in my food. I also stay away from grocery-store corn. Where I live in Florida, a lot of corn is grown for the food market. These days, it’s the GMO corn that makes it resistant to herbicides — i.e., the “Roundup Ready Corn”. There is also a corn that has the genetic material for the Bt (Bacillus thuringiensis) bacteria, which acts as an insecticide. I’m not exactly thrilled with the thought of eating an herbicide or pesticide that is impossible to wash off.
How do Tomatoes Fit In?
To the best of my knowledge, there are no GMO tomato varieties – yet. Grocery store tomatoes are safe in that respect — they just don’t taste very good. 😉
Hybrid tomatoes are not evil either; there are plenty of good ones out there. And in fact you can breed (i.e. hybridize) your own tomato variety if you wish. No labs, just testing various crosses between tomato parents until you get the traits you want. Which can take one growing season or many.
And by the way, non-GMO and organic do not mean the same thing. A tomato can be non-GMO but grown with chemical fertilizers and/or pesticides. So don’t assume tomato seeds that are listed as “non-GMO” are automatically organic.
Hopefully I’ve been able to help you understand GMOs a little better. You will have to make up your own mind, but for my part I’m glad that tomatoes are safe for the moment!
Growing tomatoes in South Florida seems like it would be easy, right? Lots of sunshine, plenty of rain. That’s good, but what isn’t is the evil twins of high heat and high humidity. In the summer, anyway. Let’s talk about growing tomatoes in South Florida.
Seasons in the Sun
For the most part, we don’t have much in the way of freezing weather here in South Florida. Sure, we do get cold snaps in the winter, and we do see the occasional frosts and freezes, but for the most part, winter is mild for the plants. If you’re able to cover your tomato plants when a frost hits, there’s a good chance it will survive.
From about late January through the end of April is our prime growing season, give or take a week or two in either direction. It’s basically mimicking what happens in the more northerly parts of the county – just several months earlier.
Our secondary growing season is from about the middle of August through to about Thanksgiving. We start out really hot, and it doesn’t start cooling down until around late September. However, by then the tomato plants are in flower and have less of an issue with setting fruit.
So….what about Summer?
Summer and the Evil Twins
It’s hot here. It’s humid. There are tons of insects. What’s not to like? 😉
Seriously, while tomato plants like the heat, they don’t like humidity — at least, not for months at a time. Our nighttime lows are the summertime highs in other parts of the country. And that is the big problem.
Tomatoes – most varieties that is – don’t set fruit well in high sustained heat, especially when they don’t get a chance to cool off at night. The large-fruited varieties are especially prone to either dropping their flowers, or not flowering at all when it gets really hot.
The humidity takes a toll as well. Various kinds of tomato blights thrive in humid weather; the bacteria and fungus move in and the leaves start turning yellow and brown or black spots – yuck!
Now, this isn’t to say that you can’t grow tomatoes in South Florida in the summer — just that it is way more challenging. I plan to do some experimenting this Summer, so subscribe and stay tuned for what I discover.
Tomato Varieties for South Florida
In the late winter through mid-spring growing season, you can grow just about any variety. Peruse the catalogs and online stores for intriguing tomatoes. Just remember that if you plan to grow your plants from seeds, you need to plant those seeds (indoors) around the beginning of December. (I have a video that I’m finishing up that talks about planting seeds; I’ll post that here when I have it ready.)
Alternately, if you’re like me in some years, you can purchase your starts from a nursery or big box store and transplant them into the garden. I tend to do a little of each, LOL.
Either way, your best bet is to get them into your garden by the middle to end of February.
Some larger-fruited varieties I have grown successfully include Kellog’s Breakfast, Cherokee Purple, Black Krim, Pineapple and Red Beefsteak. Other varieties I like are Better Bush, Eva Purple Ball, Loxahatchee, Black Prince and Druzba.
I’ve also grown Pink Brandywine — the only issue I have with it is a low production; I don’t get all that many tomatoes (although the ones I do get can be huge).
Of course I’ve grown far more than just the ones I’ve listed — these are just the ones that stand out in my memory. Wait — what about cherry tomatoes?
These are the saving grace for those of us who are homegrown-tomato-starved during the summer (and all year around, actually). Cherry tomatoes tend to still produce during the high heat and humidity. Maybe not as much as during the cooler parts of the year, but you can still grow them.
I’ve grown all sorts of cherry tomatoes, including Black Cherry, Husky Cherry Red, Isis Candy, SuperSweet 100, and Juliet to name a few. It’s getting to be late March, and I am still planting cherry tomato seeds for summertime snacking and salads. This summer I am going to try Indigo Cherry Drops and Rapunzel. I’m also going to try to keep my existing varieties (Isis Candy, Black Cherry, Juliet and Husky Cherry Red) growing.
Native Soil in South Florida
Can you say “terrible” (except for the area around Lake Okeechobee)? It’s sandy before you hit a hardpan of clay, and devoid of nutrients. The only way you can deal with it is to incorporate a lot of compost. And I do mean a lot — when I was doing in-ground gardening, I easily used 80 bags of compost when I got started. Fortunately, every year your soil will get better and better with the compost, and you will only need to add smaller amounts.
Your other options are raised beds or container gardening.
One last word is about insects. Tomato hornworms can decimate a good-sized plant overnight, and we get plenty here. Aphids can also be a problem. Fire ants are also issues (oh how I hate them!).
Nematodes can be a problem. Marigolds planted among your tomatoes will help with that. Or, do as I did — I moved everything to containers.
In the warmer, wetter parts of the year, you’ll also need to allow for mosquitoes. The tomatoes won’t suffer from them, but you will! You can’t get rid of them, but you can try to keep your garden dry (no standing water) as well as strategically place some plants that mosquitoes tend to not like around your garden. This year, I got some lemongrass cuttings and put them in 3 gallon pots. When they root and start growing well, I will transplant them to 5 or 7 gallon containers and move them around in the garden. We’ll see if it works!