Can You Grow Tomatoes in Straw Bales? (Remember This Step!)


Growing plants in straw bales is a fun and interesting idea.  The question is, will the straw bale method work for growing tomatoes, and if so, how is it done?

So, can you grow tomatoes in straw bales?  Yes, you can grow tomatoes in straw bales.  You will need to water and fertilize the straw bales to prepare them for planting and keep your tomatoes growing.  Remember to tie your tomato plants to stakes or cages to support their weight as they grow!

There are several important steps involved when growing tomatoes in straw bales.  For instance, you need to choose a good site, prepare the straw bale, and care for the plants during the season.  There’s a lot of ground to cover, so let’s dive in.

Can You Grow Tomatoes in Straw Bales?

You can grow tomatoes in straw bales, and there are some serious advantages to doing so.

First, growing in a straw bale acts as a sort of raised bed.  This allows easier access if you have trouble bending over.

straw bales
Straw bales can act as a sort of raised bed, which is helpful if you cannot bend over like you used to.

Also, a decomposing straw bale generates heat.  This heat will keep tomato plants a bit warmer during cold weather at the start of the season or later in the fall.

Best of all, a straw bale will completely decompose over time.  This means that you can compost whatever is left after the growing season and use it to feed your garden in later years.

Although straw bale gardening has its benefits, there is some preparation work to do before you start planting.

Preparation of Straw Bales for Growing Tomatoes

Before you plant your tomatoes, you will need to spend some time preparing your straw bales.  That means picking a good location, finding straw bales, and adding water and fertilizer to provide moisture and nutrients for plant growth.

Choose the Ideal Location for Your Straw Bales

Tomatoes are warm weather crops that need full sun.  This means you will need to plant them in an area that gets 6 to 8 hours of exposure to direct sunlight every day.

It is convenient to keep your straw bales near the house to make watering easier.  However, be sure to plant on the side of the house that gets the most sunlight (in the northern hemisphere, this is the south facing side of the house).

Don’t plant so close to the house that the tomatoes are completely shaded!  Also, don’t plant too close to trees, which will block sunlight once leaves start growing back in the spring.

daylight
Tomatoes need full sunlight, meaning 6 to 8 hours of direct exposure per day. Don’t plant them too close to a treeline!

The growing medium for the tomato plants will be in the straw bale, so you do not need to put your straw bale over soil.  You can place the straw bale on a patio, driveway, or concrete path.  Just keep in mind that the tomato supports will be easier to hold in place if there is soil to drive them into.

Finally, choose a location that is close to your compost pile.  This makes it much easier to clean up the leftover material from the straw bale after the growing season ends.

Buy Your Straw Bales

If you know anyone with horses, he may have some straw on hand that you can use for gardening.  Maybe you can make an agreement to trade straw now for tomatoes later in the season!

Otherwise, you can buy straw, either online or locally.  For example, Tractor Supply and Walmart carry straw bales.

Some Lowe’s or Home Depot locations may carry straw bales as well.  You might even find straw bales at Michael’s, Hobby Lobby, or other craft stores (though they may not have the big bales you want for gardening!)

Keep in mind that a straw bale can weigh 50 to 100 pounds (or more if wet!)  If you can’t lift that much weight alone, ask a strong friend for help.

straw bale
Straw bales can be extremely heavy, especially when wet. Be careful when moving them.

While you have help, put the straw bales in the location at your house that you chose earlier.  It will be difficult to move them later, especially after they get wet from watering and rain.

You can use a container to hold the straw if you like, but you do not need one.  You only need a rake, a shovel, and a wheelbarrow to clean up the remains of the straw bale at the end of the growing season.

One more note: some straw may come from crops treated with herbicides or pesticides.  This can be harmful to your tomato plants, or to the bees that help to pollinate the flowers.  Always check your source and find out as much as possible about where your straw came from (more on this later).

Add Water and Fertilizer

It will take a few weeks to prepare your straw bales for growing tomatoes.  So, start preparing the straw 2 to 3 weeks before you plan on transplanting your tomatoes outdoors.

Generally, tomatoes are transplanted outdoors after the last spring frost.  Use this tool from the Old Farmer’s Almanac to find the last spring frost date in your location.

When preparing your straw bale for growing tomatoes, the first thing to do is to add some water.  Use a watering can or a hose to wet the straw bale thoroughly.

Adding water to your straw bale will provide moisture for your tomatoes when you are ready to transplant them.  Wetting the straw will also speed up the decomposition process.

Your straw bale alone will not be able to provide all of the nutrients that your tomatoes need to grow, even after it decomposes.  However, there are plenty of supplements you can use to help things along.

The next step is to add some of these supplements to the straw bale.  This will provide nutrients for your tomato plants as they grow.

Use a nitrogen-rich supplement, such as:

  • Feather meal
  • Blood meal
  • Fish meal
  • Pelleted fertilizer, such as an NPK fertilizer (for example, 10-10-10)
fish
Fish meal is a good source of nitrogen and other nutrients for tomato plants.

Sprinkle the supplement over the straw bale, and then add more water.  Just be careful not to add too much water at once, or else the fertilizer will wash away.

Water the straw bale each day, and keep it wet to speed up decomposition.  You will likely need to water for several minutes to soak a straw bale, especially in hot, dry weather.

If you have many straw bales, it could take 30 minutes or longer every day just to water them!  Using soaker hoses can save you a lot of time – just remember to turn them on and off each day.

If you keep your straw bales watered, the composting (decomposition) process will get off to a strong start.  Decomposition occurs due to the presence of bacteria that break down the straw.  If you like, you can also add worms to help the process along.

You can tell that the straw is decomposing when the inside of the bale starts to heat up.  When the decomposition process really gets going, the straw can get up to 125 degrees Fahrenheit (52 degrees Celsius)!

Resist the temptation to get started with your garden too soon after getting your straw bales started!  Wait at least 2 weeks after you first water the straw before you start planting the tomatoes.

Remember: if you plant too early, the straw will still be too hot for your tomato transplants, which will damage or kill them!  Check the temperature in the straw with a thermostat.  It should be 75 to 80 degrees Fahrenheit (24 to 27 degrees Celsius) before you transplant your tomatoes.

Planting Tomatoes in Your Straw Bales

After you find the right spot for your straw bales and get them watered, fertilized, and composted, you are ready to plant!  All you need now is to get your tomato transplants, install supports for the plants, and put your plants in the straw bale.

Grow or Buy Your Transplants

You can buy tomato transplants online or at a local garden center, such as Lowe’s or Home Depot.  You can also grow your own tomato transplants from seed.

If you decide to buy tomato transplants, choose ones that are healthy and well-established.  If they are too tall and thin (“leggy”), then they might have trouble growing.

If you decide to start your own tomato plants from seed, be sure to start them well in advance.  The Old Farmer’s Almanac suggests planting tomato seeds indoors 6 to 8 weeks before the last frost date in your area.

tomato seedling
Start tomato seedlings indoors 6 to 8 weeks before the last spring frost date.

For ideal germination, tomato seeds need moist soil at temperatures of 65 to 85 degrees Fahrenheit (18 to 44 degrees Celsius).  You can learn more about tomato seed germination (and how to speed it up) in my article here.

When choosing which tomato varieties to grow, remember the difference between determinate and indeterminate tomato varieties:

  • Determinate tomato varieties grow shorter (3 to 5 feet, or 0.9 to 1.5 meters) and tend to bear fruit only once in a season before they stop production.
  • Indeterminate tomato varieties grow taller (6 to 8 feet, or 1.8 to 2.4 meters) and bear fruit until frost kills them.

For straw bale gardening, determinate (shorter) tomato varieties might be a better choice.   Indeterminate varieties may grow too tall and produce too late in the season.

At that point, the straw bales are really starting to decompose.  All of these factors (tall tomato plants, heavy fruit, and decomposing straw bales) can cause the tomato plants to fall over.

To avoid this problem, you can place your straw bales near a fence and tie the tomatoes up as they grow.  You can also use supports for your tomato plants, such as stakes or cages.

Install Supports

There are lots of reasons to use supports for your tomato plants, especially if you want to grow the taller indeterminate varieties.  For one thing, supports help to keep your tomato plants from falling over later in the season, as they get taller and bear more weight when they produce fruit.

Supports also keep your tomato plants off the ground.  This reduces the chances of a soil borne disease infecting your plants, and it keeps the fruit clean.

Finally, supports allow your tomato plants to grow straight up, instead of across the ground.  This saves garden space, and is especially helpful in limited space or square foot gardening systems.

To provide support for your tomato plants, the first step is to choose the type of support.  You can use:

  • Stakes (great for taller indeterminate varieties)
  • Cages (ideal for shorter determinate varieties)
  • Trellises (good for taller indeterminate varieties that produce fruit more than once)
  • Ropes (can be used for both determinate and indeterminate varieties)
  • A-frames (can be used for both determinate and indeterminate varieties)

You can buy stakes, cages, rope, and trellises at garden centers or online.  You can also buy the materials to make your own custom trellis or A-frame at these stores.

tomato stakes
Stakes are a good choice to support indeterminate tomato varieties, which grow much taller than determinate varieties.

It is a good idea to put the supports in place before the tomato plants start growing too large.  Ideally, drive the stakes into the straw bales (and into the ground below if growing over soil) before transplanting the tomatoes.

No matter which support system you decide to use, you will need to find some way to tie the tomato plants to the support as they grow.  One method is to use garden twine to tie the tomatoes to the supports every 6 to 12 inches (15 to 30 centimeters).

You can learn more about the various types of tomato supports (and how to tie tomato plants) in my article here.https://greenupside.com/why-do-tomato-plants-need-support/

Transplant Your Tomato Plants

Finally, the preparation work is finished – now it’s time to transplant your tomatoes!  First, remove some straw and decomposed material from the top of the straw bale to make a hole about 2/3 the height of the tomato plant.

For example, if the plant is 9 inches tall, then make the hole 6 inches deep.  To learn more about why to plant tomatoes so deep, check out my article here.

Then, put the tomato transplant in the hole, and fill in the hole with soil (ideally, improved with compost) to the top of the straw bale.  You can put a little straw over the soil to act as mulch, which will keep the soil warm and retain water.

Caring for Your Straw Bale Tomato Plants

Now you have transplanted your tomato plants into the straw bale.  It’s time to let them grow, while taking care of them along the way.

Proper care includes watering and fertilizing as needed.  You will also need to tie the tomato plants to their supports every so often, to prevent them from falling over.

Water Your Straw Bales Often

Water your straw bales often to keep the straw and compost moist.  Tomato plants will die of dehydration without enough water, whether they grow in soil or straw!

As mentioned before, drip irrigation will save you some time and effort in watering.  Remind yourself to turn the water on and off at the same time every day.  Watch the weather and make water adjustments upwards (for dry heat waves) or downwards (for heavy thunderstorms).

If you tend to forget things, it might be better to use a hose with a spray attachment for watering.  That way, you can easily control how much water each straw bale gets.

It is possible to over water, so be careful and pay attention to the signs your plants will give you!  To learn more about over watering, you can read my article here.

Add Fertilizer during the Growing Season

As the growing season goes on, add some more of the fertilizers mentioned earlier (feather meal, blood meal, fish meal, or pelletized fertilizer).  Sprinkle some of the fertilizer on top of the straw bales, and water it in so it will move through the straw to the tomato plant’s roots.

Be sure to follow the instructions on the fertilizer label when you use it.  Avoid over fertilizing, since this can burn your plants with excessive nitrogen or other nutrients.

Tie Your Tomato Plants to their Supports as they Grow

As your tomato plants grow, you will need to tie them to their supports to prevent them from falling over.  Do this every 6 to 12 inches (15 to 30 centimeters) as the tomato plant grows.

Garden twine is useful for this purpose, since it will hold up well for one season and then decompose later on.  You can also opt for reusable plant ties like these ones from Gardener’s Supply Company.  Just remember that you will have to untie them and remove them at the end of each growing season.

Pollinate the Tomato Flowers

You will only need to pollinate the tomato flowers by hand if there are no bees in your yard!  A lack of bees could happen for many reasons – one of which is the use of pesticides on nearby lawns.

If pollination is a problem, then you can pollinate your tomato flowers with any of these tools:

  • Cotton swab
  • Toothbrush (electric is better!)
  • Tuning fork
  • Toothpick, pencil, or stick
tomato flower
Your tomato flowers may need pollination if no bees are present to do the job for you.

You can learn more about how to hand pollinate tomato plants in my article here.https://greenupside.com/are-tomato-plants-self-pollinating-plus-how-to-pollinate/

Cleaning Up Straw Bales at the End of the Season

Rake up any leftover straw, compost, and dead tomato plants from the season.  Then, put it all in your compost pile.

Once the compost ages and decomposes, you can use it in your garden, in a raised bed, or for potted plants grown indoors.

You can also add grass clippings, fallen leaves, and fruit or vegetables from kitchen scraps to your compost pile.  You can learn more about how to make your own compost in my article here.

compost bin
You can put straw, grass clippings, leaves, and fruit or vegetable waste in your compost bin.

Straw Bale Gardening Problems

There are a few potential problems to look out for when using straw bale gardening to grow tomato plants:

  • Lack of nutrients – without proper fertilization, you won’t be able to grow much in your straw bales.  Use good soil to cover your tomato transplants when you put them in the straw bale, and water in fertilizer as you add it throughout the growing season.
  • Herbicides in straw – some straw comes from plants that are treated with pesticides (to kill bugs) or herbicides (to kill weeds).  Unfortunately, pesticides can also kill bees, which will prevent your tomato flowers from being pollinated as well as they could be.  Herbicides kill weeds, but they can also kill plants you want to grow, including your tomatoes!  Check the source on any straw you use.
  • Seeds in hay – if you decide to use hay instead of straw, keep in mind that seeds in the hay can easily grow into weeds.  These weeds will compete with your tomato plants for nutrients and water.  They can also end up in your garden if you add the leftover hay to the compost pile at the end of the season.

Conclusion

Now you know how to grow tomatoes in straw bales, and what steps to take to get started.  You also know how to care for your plants during the season to ensure a good harvest.

I hope you found this article helpful – if so, please share it with someone who can use the information.  It’s time to get your straw bales ready and grow some tomatoes!

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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