Are you having a hard time figuring out how to approach Spring Gardening in our sometimes unforgiving Florida climate?
We are very fortunate to have the warmth that we do, with limited cold snaps, and usually plenty of rain.
But for people who learned to garden where there are climate-based seasons, or who have learned through resources meant for places with actual seasons, it can be so difficult to navigate when to garden in Florida.
And that’s where your local neighborhood Shell’s Feed & Garden Supply can help you.
We’ve been gardening here a long time. Our store has been serving the Tampa Bay area since 1961. Back then we were surrounded by farms growing crops and raising livestock. As those farms have been eaten up by the city, we’ve turned our focus on to growing your own backyard vegetables for your family, and to urban farming.
So, with a base guidance from the UF IFAS program, along with our personal experiences gardening in Central Florida, we’ve got a lot to offer to those who are figuring out planting seasons, like Spring, here in Florida.
Sure, we’ve got a class for that! I hope you’ll join me for that – this class is part 3 of a 4 part series that I’ve been putting together seasonally. We started in Fall 2019, then we had a Winter Class, now this is the Spring class. Of course, there will be a Summer class as well.
In the meantime, though, I’ve got a couple of tips for you right here to get started.
Forget about the First Day of Spring
If you’re waiting until the Spring Equinox to start thinking about planting because that’s what your favorite gardening magazine told you to do, I have sad news for you. In Florida you’re WAY too late for many crops.
By the time the Equinox rolls around, it’s already blistering hot outside, and our wet season will be starting soon, which means your tiny seedlings will be more susceptible to fungus, and heat withering.
In Florida, you can start planting seeds in January (or even mid/late December!) for Spring. Yes, I said December. And January.
Also, our strong and healthy Starter Plants arrive usually right around February 1st at our store – and we plan it that way for a reason. Starter Plants can go in the ground starting in February. You can also plant lots of different kinds of seeds in February.
Is there risk of frost this early in the year? Sure. Some years we get a late nip in the air. But there’s ways to make sure that your seedlings survive, and we can tell you all about how to make sure you’re protected. All you have to do is ask.
Container Plantings are a sensible option for Florida Spring Gardening
We’re here to support you in however you want to grow your veggies, or flowers, or trees, or whatever you’ve got going on. Many people choose to plant in the ground, and that’s totally great!
If you’re planting native plants, you really don’t have to do anything to the soil, they’ll be just fine with what you’ve got.
Ground plantings, like raised beds, or mounds, for things that are not native to Florida take some extra special care in the form of soil amendments and fertilizers. This is because we’re trying to force plants that aren’t used to our sandy soil to grow where they don’t really belong. So, we have to amend the soil and add the nutrients that our soil is missing for them to flourish. With a little prep ahead of time. this is definitely do-able.
BUT…you can better control your plantings using containers. You can mix your own soil, add your own nutrients, protect your plants from soil-borne illnesses, and control their sun, water, and climate, when they are in a container.
As far as containers go, you probably know that we’re Tampa’s Earthbox Authority, and we’re HUGE fans of what the Earthbox can do for the things you want to grow, like vegetables and flowers.
Earthbox makes it SO EASY to grow your own. In fact, we want you to experience the joys of Earthbox so much that we have a class for that!
There are also all manner of sizes of black plastic reusable nursery tubs, galvanized and rubber stock tanks, and all kinds of container planting options available at our store too.
We can show you what you need for all these, and you’ll have great results.
Your Spring Options Are Nearly Limitless Here
Spring Gardening in Florida, starting in January, really allows you nearly limitless possibilities on what you can grow. You can still plant cold-weather crops – it’s still cool enough for lettuces and collards and kale, for example, and you can plant warm weather crops like peppers, tomatoes, okra, and beans too.
Spring planting time is when you can plant and enjoy the most diverse gardens here. So, take advantage of our good fortune. Try some new veggies and flowers. Get creative with containers and raised beds.
We’re here to help you. We can answer questions and give you advice if you run into a problem. That’s what we’re here for.
As you might imagine, Fish Emulsion 5-1-1 is exactly what it says it is. It is a combination of leftover fish from the commercial fishing industry. It’s a fantastic natural source of nitrogen right away for plants needing a bit of a boost.
One caution with Fish Emulsions – they get a little stinky for a little while. I suggest using it during your neighbor’s working hours while they’re away from the house…unless you hate your neighbors, then Saturday morning is definitely the best time. Ha! 😉
This soil amendment is not found often available, as most of us don’t need it. It’s only used for soils where there is a LOT of thick clay (not usually Central Florida) or where soil is very salinated and salt needs to be removed from it (now that’s very possible here).
Gypsum can be harmful to other types of soil, such as sandy soil, as outlined in this very helpful article that summarizes the use of Gypsum (which is actually just calcium sulfate). I advise use with extreme caution. Have your soil tested first to make sure you actually need it!
Sources of Iron are important for any green plant. It is a necessary element to make Chlorophyll which is how plants manufacture their food (via photosynthesis).
One of the most common sources of Iron is a fertilizer called Milorganite, which is pelletized deceased poop-eating bacteria from water treatment facilities at Jones Island (Milwaukee, WI). It is organic and does not cause issues with nitrogen runoff. The history of Milorganite is pretty interesting, you should read more about it.
We also have a liquid Chelated Iron and a Pelletized Iron as well. Most people apply it to their lawns as a “quick green up” during the year when grass and landscapes can suffer in the Florida heat.
Kelp has many nutrients that land-plants need, and it can be sustainably harvested too.
Kelp Green is a wonderful ocean-based seaweed extract and fish emulsion that really offers a one-of-a-kind opportunity to use kelp in your garden without harvesting it from the beach yourself. It’s a masterful way to get a large assortment of micronutrients to your plants that is not found in other types of chemical pelletized fertilizers. These micronutrients include antioxidants, amino acids, vitamins, hormones, and minerals too.
One of my favorite things to do on fertilizer bags is to look for the minor elements they contain – also called the “micronutrients” in some cases (but micronutrients are not just the minor elements…skip that last part there if it confused you!). You can buy a fertilizer that is just a bunch of the minor elements thrown together too which can be applied to everything without worrying that it will harm anything. All plants need these minor elements.
You see, the macronutrients, also called “Major Elements”, are the N-P-K numbers you see on the fertilizer bags. But depending on what you’re targeting, other minerals/elements might be added to help that specific kind of plant. And it’s fascinating to see what certain plants need to thrive.
The Minor Elements include: Boron (B), Chlorine (CI), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo), and Zinc (Zn)
Potash is another word for Potassium, in garden-speak. The N-P-K on fertilizer bags is sometimes called “Nitrogen-Phosphorus-Potash” even though “K” is the Periodic Table letter for Potassium.
Why the name Potash? Actually, I didn’t know, so I looked it up. The word Potash comes from the method that Potassium was originally isolated from wood ash. The ash was placed in a large iron pot with a solvent and boiled until the liquid leaching agent was dissipated. The isolation process is much different now, of course.
Muriate of Potash is 50% Potassium and 46% Chloride. Both of these elements are essential for plant health, thus if your soil is potassium deficient this is a good choice to replenish it because it is very highly absorbable.
In honor of the City of Tampa fertilizer ban ending this week, I thought it might be fun to answer one of our most asked questions:
“What fertilizers am I supposed use in my garden, and how do I know which ones are needed for each plant?”
Gosh, this is a fun one – and we get asked questions similar to this all the time. So, I’m ready to dive in to decoding fertilizers today.
The first thing I think you need to know about fertilizers is what the 3 numbers on the front of the container mean. These numbers indicate the amounts of the Macronutrients of Nitrogen, Phosphorus, and Potassium in the formula.
Often called the “N-P-K”, which stands for “Nitrogen-Phosphorus-Potassium,” this fertilizer indicator shows you two things: 1) The ratios of nutrients relative to each other; and 2) How many pounds of this product you would need to add 1 pound of that nutrient to the soil.
N-P-K Indicates Relative Ratios
The N-P-K numbers give you what is called “guaranteed analysis” that shows the amounts of the macro nutrients in each bag. It sets the standard for the contents of each bag.
For the ratios, a 10-10-10, or 3-3-3, will have the same exact amounts of all 3 nutrients throughout the entire bag. A 12-6-8, or 6-4-6, will have different amounts of nutrients throughout the entire bag. Higher numbers mean more of that nutrient was added to that formulation, in relation to the relative amounts of the other nutrients.
Since all these different formulations exist, it stands to reason that different ratios of nutrients are good for different plants. In fact, specialty ratios have been developed for certain types of plants. This is why you see specialty fertilizers such as Rose, Azalea, Palm, Citrus, Strawberry, Blueberry, and more.
These special formulations have been shown to increase the growth and production of these specific plants because of the ratios of the three main nutrients. It is based on how those plants assimilate nutrients, how they use them, and observational studies of which nutrients give the maximum amount of the desired result. Yep. it’s science.
Often, these specialty fertilizers will also have additional ingredients too, like micronutrients, humates, mycorrhyzae, etc – check out the back of the bag to see what goodies are in there for those special types of plants.
Alright, up next, it’s time for some math. Ugh, adulting is hard.
N-P-K Indicates Relative Weight
Now, speaking about the second characteristic of the N-P-K rating, the amount to apply to reach 1 pound of that nutrient in the soil, we need to do a little math.
Here’s a simple example: Shell’s 10-10-10 N-P-K fertilizer indicates that you will need 10 pounds of the fertilizer to add 1 pound of each of the nutrients into the soil. You do this math by taking 100 (indicating 100%) and dividing it by 10.
100 / 10 = 10 lbs of fertilizer is needed to yield 1 pound of nutrient applied to soil.
If the N-P-K numbers are all different, like our Shell’s 4-6-8 Citrus Fertilizer, then you’d take each of those numbers and divide them into 100. Your answers will tell you how many pounds of that fertilizer you’d need to put 1 pound of that nutrient into the soil, like this:
So basically the N-P-K numbers are “weights” in a ratio format. Basically the higher the number, the LESS fertilizer you need to achieve the same result.
I know, it’s a little confusing sometimes, especially when you’re dealing with the N-P-K’s with different values for each nutrient.
What Nitrogen Does for Plants
Nitrogen is essential for healthy plant growth. It is an essential component in the process of photosynthesis, and as such it is needed to grow leaves and the stems to support them.
Plants with not enough nitrogen will show yellowing leaves that fall off easily. Plants with too much nitrogen will have leaves that yellow then brown and become “crispy” as the whole plant shrivels and dies (nitrogen burn). So nitrogen has to be in the right balance to help plants.
What Phosphorus Does for Plants
Phosphorus helps plants convert nutrients taken in by the roots and converting them into building block for the plants in their growth process – for example, making proteins that keep stems strong. Phosphorus is essential for root development.
Plants with not enough Phosphorus will have a classic “failure to thrive” identity – they will be small, and will have difficulty flowering or fruiting. Their root systems will be under-developed. They may have either a very bright green or a purple hue to them – these are both signs of Phosphorus deficiency.
What Potassium Does for Plants
Even in modern science today, the specific interactions of Potassium with plants remains a mystery. That said, we know what happens with plants when they don’t have enough, so we can extrapolate from that.
Potassium increases the rate of growth of the whole plant. It makes them use water more efficiently and makes them more drought resistant. With the correct amount of potassium plants are able to fight off disease and pests. They also produce more flowers, and fruits.
Potassium deficiency is hard to spot, but sometimes in the older leaves there will be brown spots, yellow edges of the leaves, yellow or brown veins. Overall the plant will not perform well.
How Do I Know If My Soil Has What My Plants Need?
Well, that’s pretty simple, really. Soil can be tested!
There are soil test kits – we carry them. There is also your local UF Extension office – they can test your soil for you, and if you need further testing, they have resources where you can have a more full analysis of your soil done for you.
If you’re serious about finding out a full analysis of your soil with a full report of what you can do to make it ideal, there are private and/or commercial facilities that will take your soil and test it with full reports.
I found a small list of providers at Fine Gardening’s website, edited to remove links that no longer work.
Woods End Research Laboratory PO Box 297, Mt. Vernon, ME 04352; 207-293-2457 www.woodsend.com
I definitely suggest starting with the local Extension service. They’re there to help!
Diagram of Plants and How Macronutrients Help Them
Side by Side Comparison of Nutrient Deficiencies
What Do I Use For My Vegetable Garden?
Now that you know all of this great information, the choice should be easy.
A well balanced fertilizer is great for your vegetables and herbs to help promote growth of the whole plant. Formulas like Shell’s 6-6-6, 8-8-8, and 10-10-10 are great for gardens. If you love the idea of organic food growing, Shell’s 3-3-3 Organic Garden Mix Fertilizer is AMAZING for gardens, lawns, landscapes, ornamentals…really anything you want to grow.
For your trees, ornamentals and specialty plants, there are a wide variety of specialty fertilizers available for them. Ask us when you get to the store and we’ll point you in the right direction.
I will say that it is very beneficial to have your soil tested for the Macronutrients. Your soil may not need fertilizer, and adding more would contribute to leaching of these nutrients in the the ground water and our beautiful Gulf of Mexico. When we add too much nitrogen, our porous soil allows the nitrogen to leach out, adding lots of nitrogen to our water table and our ocean. Then algae get a growth boost, and we have what’s called “red tide.”
“It’s like the old adage – too much of a good thing can be bad.”
The fertilizer ban legislation happened because of humans using too much chemical fertilizer in the environment and not planting plants that are native to Florida which tolerate the “challenging” soil we have here. Our soil is just fine for Florida native and naturalized plants – we only find it challenging because we try to grow things that normally wouldn’t grow here, and chemically force them to survive.
Compost, clean dry leaf litter, pine bark or needles, straw/hay, old mulch, and wood chips are all great organic matter to add to your soil. As it decomposes over time, all of the NPK nutrients in that plant matter is eaten by the critters and microbes in the soil. The Nitrogens, Phosphorus, and Potassium in those materials are thus made available to the plants that are growing now.
It takes time, but amending with organic material is the best long term way to ensure that your soil has plenty of N-P-K and other nutrients for your plants. And…organic materials can be collected from your yard either for free, or it’s kitchen scraps and other waste that would have gone to the landfill…which you can collect and compost yourself.
I hope this fertilizer tutorial was helpful to you! Let me know if you have any questions.