7 Things to Put in your Tomato Planting Hole for your Best Harvest Ever!

I’m so excited about tomato season!  Tomatoes are heavy feeders, and can actually be a bit finicky. Because of this, what you put into the tomato planting hole at the time of planting is super important to get that little baby tomato off to a good start.

What you put in your tomato planting hole determines the health of the tomatoes
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Tomatoes have long been a huge part of my summer vegetable garden— as long as I can remember. I’ve experimented with a whole lot of different tomato planting hole variations, but the combination below has worked out the best for me for super healthy tomatoes.  

This tomato planting hole ‘recipe’ works, because it addresses the nutritional needs of the tomato as well as boosting the immunity, helping your plant not only to grow lots of big fruit, but also to resist both diseases and pests.

My tomato plants grow to be 7 feet tall or more.  I had to make my own cages because store bought cages are too small.  We grow a lot of tomatoes each year, and what I’ve found with this planting hole recipe is not just that it produces healthy plants, but HUGE fruit and high yields.

What you put in your tomato planting hole determines the health of the tomatoes
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One of the first tomatoes of the season this year

The Soil

Before you can even think about the amendments to the planting hole, let’s talk about your soil.  Your soil should be light and fluffy; working in a 50 percent compost mixture to your soil and turning it in will help to aerate and add in nutrients.

I have raised beds, so I actually remove all of the soil about every 5 or 6 years and replace it with new organic compost. In truth, I do it so frequently because that’s about the time it takes for the hardware cloth at the bottom of the bed (gopher deterrent) to start rusting. Check out my post on building raised beds. But the vegetables really benefit from the fresh compost.

What you put in your tomato planting hole determines the health of the tomatoes
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To make my life easier when planting rows of tomatoes, I get my amendments early in the season. I transfer them to easy-pouring containers, and keep everything together in one of these TubTrug plastic garden tubs. An old measuring cup specifically for the garden is also useful to keep with the amendments.  Then, I have all the necessary ingredients at my fingertips come planting time.

Preparing the Tomato Planting Hole

Before you can add the amendments, you must first dig the hole. It should be at least twice as deep as the transplant. To streamline the process, I dig all my holes at once, and go right down the line adding the amendments to each hole. 

The order I put everything in the hole is important, too.  On the bottom of the hole are the things the tomato plant doesn’t need right away. On the top of the hole are the things the little seedling will use immediately. 

What you put in your tomato planting hole determines the health of the tomatoes
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Water deeply inside the hole prior to adding the amendments. Water it well while the hole is open to make sure the water gets way down into where the roots of the plant will be. The water deep down in the root area will stay moist for a very long time when covered by more soil and either mulch or red water wells. This will allow your irrigation system at the top of the soil to wick through and maintain an even moisture level throughout the layers of soil.  

Uneven moisture contributes to blossom end rot. Also, make sure to water *before* the amendments go in the hole so that you don’t wash them away. 

Once the hole is dug and watered, start adding:

1. Crushed or Ground Eggshells

What you put in your tomato planting hole determines the health of your tomatoes. Eggshells increase calcium and fight disease.
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Use about 4 eggshells per plant. The calcium is critical for your plants to prevent blossom end rot. These go on the bottom of the hole, because they will be used by the plant last of all the planting hole amendments – during the formative stages of fruiting. I save our egg shells after breakfast through the winter just for this purpose.  Since we use our own hens’ eggs, we do not wash the shells, but if you are using store-bought eggs, you may wish to bake them in the oven to kill any microorganisms.

Grind the eggshells using an old coffee grinder or even a food processor. I have one reserved for garden tasks like this, and also grinding up dried peppers into spice blends. Crushing the eggshells by hand is also an option, but in my garden, it seems to take longer for the plant to assimilate the larger chunks. The larger shell pieces do not easily biodegrade by the time the tomato plant needs the calcium.  (approximately 4 months from sprout to fruit production).

If you decide to grind, do so in a well-ventilated area. The ground eggshells are very fine and can irritate if inhaled.

2. Aspirin / Salicylic Acid

Use 2 tablets  – they will boost the tomato plant’s immune system, increase stress tolerance, and help the plant tolerate extreme heat or drought conditions. The aspirin will prevent fungal infestations, and will also assist the plant through extreme heat. A heat wave — above about 85 degrees for several days — will cause some varieties to cease pollination, stalling fruit production until the heat passes.  You can just drop two aspirin right into the hole – these dissolve readily in water, so I do not crush them. 

3. Bone Meal Fertilizer

What you put in your tomato planting hole determines the health of your tomatoes. Bone Meal and aspirin are important nutritional additives for tomatoes
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Phosphorus is one of the most important components for tomato health, and I add it in several different forms for the different stages of plant growth. You’ll need 1/2 cup of bone meal (phosphorus) in the tomato planting hole. This is critical for blossom production. The more flowers, the more tomatoes. Also, the phosphorus actually also increases calcium availability and better enables the seedling or start to acclimate to its new environment.

Many websites claim that Epsom salt (magnesium sulfate) is good to enhance bloom on tomatoes. Some even claim that it prevents blossom end-rot. While it does promote blooms, unfortunately, magnesium sulfate could also interfere with the plant’s ability to absorb calcium. Tomato plants need extra calcium to prevent blossom end rot. Therefore, applying magnesium sulfate could actually promote blossom end-rot on your tomatoes and should not be used unless a soil test has indicated a magnesium deficiency. Best to stick with bone meal to provide the needed phosphorus for blossom production. Epsom Salts are fine to apply in moderation to your roses, just not vegetables.

Bone meal is easy to find in garden centers in a fine consistency.

4. Fish Meal Fertilizer

1/2 cup. Fish meal adds in critical nitrogen, which improves root growth and stem girth. I don’t use fish-heads or other fish parts, as some people do, for a few reasons.  First, fish heads are smelly and attract wildlife.  In the past, I have had some digging at the root-balls of some of my plants. When your soil is in a raised bed, it is light and fluffy because you don’t walk on it.  Therefore,  it is pretty easy for a determined raccoon or other rodent to dig a foot or two down.  Second, when you water sparingly, a fish head will sit in the soil without easily decomposing.  

To ensure the nitrogen is immediately available for the tomato plant,  (and because I don’t want  to revisit it when I turn the soil at the end of the growing season!!) I swear by fish meal.  All of my veggies get fish meal at the time of planting to promote a healthy root system.

5. Granulated Tomato Fertilizer

Tomatoes are heavy feeders, so in addition to the calcium, nitrogen and phosphorus amendments above, I also add in a handful of organic granular tomato formulated fertilizer at 4-6-3. (nitrogen/ phosphorus/ potassium). The balanced granular fertilizer will release more slowly into the soil as the tomato grows to make sure it has enough food to keep growing all season long.


The amendments above go in the bottom of the tomato planting hole don’t touch our precious little tomato roots….yet. You’ll want to separate the amendments added so far from the transplant root zone in order to prevent your tomatoes from ‘burning’.  

The roots will very soon grow down into the amendments on their own, and that’s fine, but we just need to give the little sprouts a chance to settle in to their new surroundings prior to meeting all those soil amendments. The amendments are rich and hot, and could possibly burn the tender plants if introduced before recovery from the transplant.  

However, the last two amendments, below, CAN and should touch the root ball of your tomato seedling or start.

6. Organic Earthworm Castings

I use a few handfuls of worm castings to separate the above amendments from the tomato roots.  Worm castings are fantastic for all of your veggies; they provide all sorts of nutritional macronutrients which will help your tomatoes thrive.  Try to get as pure castings as you can.  If you don’t have worm castings, you should still separate the plant roots from the amendments with some well composted manure or fresh garden soil.

7. Mycorrhizal fungi

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The last thing I put into the tomato planting hole before planting – and the one amendment which does need to touch the roots in order to be effective: Mycorrhizal fungi. This additive is sold by xtreme gardening under the brand name MYKOS. This fungi attaches itself to the tomato’s root system and creates a symbiotic relationship with the plant to help it fight disease.  I started adding this to the hole in the last few years and have seen an amazing improvement in the overall robustness of the plants.

Filling in the Tomato Planting Hole

Ok, the amendments are in. Now you need to back fill the hole and water deeply. Do not press down on the soil – watering will do that for you.  Tomatoes need the oxygen and compacted soil will be harder for the young roots to penetrate.

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I then put a red Tomato Halo over each plant to prevent water evaporating from the soil too rapidly, and a plant teepee or wind protector to shield the young plant from wind and harsh sun.  The teepee will come off in about two weeks, once the plant has recovered from the shock of transplant and started growing in its new location.  The red water well ring or halo stays on for the entire season to cool the roots during the hot months and to direct supplemental water to the root zone. 

Ongoing Maintenance for your Tomatoes

Once the tomato is planted and the water irrigation setup, I don’t have to do anything, right? Well, yes and no. To get the extra large fruit, you will want to add a phosphorus fertilizer (“Superbloom” or “Bold Bloom”) on a regular basis, as according to package directions. Depending upon the strength of the phosphorus, you will want to add it either weekly or monthly, May through September. If the phosphorus is dissolved in water, the recommendation is usually a weekly application. However for time release granular, you generally apply it once monthly.

Phosphorus not only aids blossom production, but it also increases fruit size when applied after fruiting has begun. I use a granular application and apply on the first day of each month to make sure I remember.

Also read these tips for growing healthy tomatoes. I talk about the soil, the siting, cages you’ll need, and a whole lot more! Or head on over to this one about understanding and diagnosing tomato issues.

The results will speak for themselves, I can guarantee you will have the healthiest tomato plants you have ever had! Indeterminate varieties will likely be taller than you are, without overwatering. 

What you put in your tomato planting hole determines the health of the tomatoes
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