Raised Beds

What is the Best Soil for Herbs in a Raised Bed?

“What soil is best to use for my herbs in a raised bed? I have lemon balm, mint, basil, and thyme.” Stacey of Brooklyn Park, Minnesota

Answer: Our Black Gold Natural and Organic Raised Bed Potting Mix is specially formulated for raised beds and has all of the characteristics needed for growing herbs, including good drainage, ample organic matter, and a neutral pH. Additionally, I always recommend that gardeners mix a little natural topsoil into their raised beds at a ratio of one part topsoil to two parts bagged mix. The addition of natural mineral soil will increase the longevity of the mix and provide natural microbes and minerals.

The lemon balm and basil will grow beautifully in the organic-rich mix. In the areas where you plant thyme (or lavender and sage, for future reference), I recommend the addition of a fast-draining mineral amendment, such as sand or gran-i-grit. A small bag will help. Mint is a very aggressive herb that will completely take over a raised bed, so I suggest growing it alone in a large pot.

After your herbs have initially been planted, water them every other day to help them become established. After a couple of weeks, you will only need to water if the soil becomes dry in the absence of rain. Add a slow-release fertilizer for vegetables and herbs at the beginning of the season to ensure that they grow their best. (Click here for more information about growing essential culinary herbs.)

When determining how the amount of mix to add to your beds, use this formula:

How to find soil volume for square or rectangular raised beds:

To find the amount of soil you will need, determine the volume of your square or rectangular bed by measuring its length, width, and height. Then use the following formula: V = L x W x H.

V = soil volume
L = bed length
W = bed width
H = bed height

So, if your bed happens to be 6 feet x 4 feet x 1.5 feet, multiply 6 x 4 x 1.5 = 36 cubic feet. Our raised bed soil is sold in 2.2 cf bales. To determine the amount of bagged soil you might need (36 cubic feet/2.2 cf bales= 16). If you plan to add topsoil at a 1:3 ratio, then you will need 2/3 mix (24 cubic feet (10.66 2.2 cubic foot bags of raised bed potting mix)) and 1/3 topsoil (12 cubic feet of topsoil). If you want to buy topsoil by the yard, then you must know yardage. Divide the answer in cubic feet by 27 to get the number of cubic yards you might need (36/27= 1.3 cubic yards).

Happy gardening,

Jessie Keith

Black Gold Horticulturist

What Are the Benefits of Raised Bed Gardening?

“Are raised beds easy to grow in and maintain? I live in North Carolina. During the winter can I put a tarp-type Greenhouse over them to help protect vegetables from the cold.” Question from Karen of Rougemont, North Carolina

Answer: There are many benefits to growing in raised beds and very few downsides. Here are the pros and cons of raised bed gardening, followed up by methods to help maintain your garden through winter.

Pros of Raised Bed Gardening

Deeper, Lighter Soil: If you fill your raised beds with good soil from the start, it helps root crops grow deeper and all plants set deeper roots for higher yields. We recommend using either Black Gold® Natural & Organic Raised Bed & Potting Mix or one-part ground soil to two-parts Black Gold Garden Compost Blend. If you have more alkaline soil, the addition of Black Gold® Natural & Organic Canadian Sphagnum Peat Moss is helpful. Top off the beds with additional quality topsoil or amendment yearly.
Easier Weeding: Raised beds have looser soil, are higher, and often cover a smaller area, making them easier to weed. It’s also easier to harvest after rain and stay clean when beds are surrounded by pebble, straw, or cut grass.
Easier Harvest: Because they are raised, the beds are easier to harvest and replant.
Easy Planning and Rotation: When you have just a few geometric beds, it is easier to design plantings for yearly rotation (Click here to learn more about the importance of rotating crops)

Cons of Raised Bed Gardening

Initial High Cost: Raised beds are not inexpensive to install if you start out right.
Less Space for Big Crops: Unless your beds are large and you have trellising, you have less space for large crops like vining pumpkins, squash, and melons or multiple rows of corn.
Need Replacement: Eventually your beds will need to be replaced. Metal and plastic options last longer. Cedar raised beds are also long-lasting. Never use treated wood to create raised beds because the wood contains heavy metals that can leach into the soil and be taken up by crops.

Raised Bed Covers

Floating hoop covers are the easiest and best insulating covers to extend growing in raised beds. You also may consider adding a cold frame to your raised bed plan. They make it easiest to continue growing herbs and greens through winter. (Click here to learn more about cold-frame gardening.)

I hope that this helps!

Happy Gardening,

Jessie Keith

Black Gold Horticulturist

What Is The Best Soil for Raised Beds?

“I built 2 beds measuring 4′ x 16′ and 2 foot deep. I don’t think I need a Black Gold mix for the bottom half. What is something I could [add to] the bottom half of the boxes? Also are Black Gold products meant as a supplement to the soil or a soil replacement?” Question from Kevin of Rome, Georgia

Answer: We have many amendments and soils suitable for raised bed gardening, but we now sell a natural raised bed soil that is specially formulated for your type of garden. Black Gold^® Natural & Organic Raised Bed & Potting Mix is just for raised bed gardening, is sold in cost-effective large bales and is OMRI Listed for organic gardening. If you wish to supplement with additional soils or amendments, try the following bulk and/or bagged options.

Quality screened bulk compost, leaf compost, or mushroom compost – These are all rich and fortifying but high in organic matter, which eventually breaks down over time and needs to be replenished.
Quality screened bulk topsoil – Topsoil contains mineral soil as well as organic matter, so not all of its components will break down over time.
Bagged compost, such as Black Gold Garden Compost Blend – This is a good option for smaller-scale raised bed gardening. Treat it as you would bulk compost.

Products sold in bulk are generally available at large landscape supply centers and are sold by the yard. Add topsoil of compost at a ratio of one part topsoil or compost to two parts bagged mix.

Before ordering any soil, be sure you know how much you need by using the soil application formula. Also, be sure to feed your soil with quality fertilizer formulated for vegetable gardening.

Soil Application Formula

To find the amount of soil you will need, determine the volume of your square or rectangular bed by measuring its length, width, and height. Then use the following formula: V = L x W x H.

V = soil volume
L = bed length
W = bed width
H = bed height

Happy gardening,

Jessie Keith

Black Gold Horticulturist

(For more tips click here for a full overview of how to prep a new vegetable garden from start to finish.)

I hope that these tips help.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

What Is the Best Black Gold Soil for Raised Beds?

“I have several raised garden beds (6’x3′ and 2’x2′) both 18+ inches deep for vegetables. I am debating between the “natural and organic potting mix”, “organic flower and vegetable soil”, and “natural and organic raised beds and potting mix”. Is there a clear choice here or would I be good with any?” Question from Lars of Chicago, Illinois

Answer: All three of these products work well for raised bed growing, but our new Black Gold Natural and Organic Raised Bed Potting Mix is specially formulated for raised beds. If I were to choose from the three, it would be my pick. Additionally, I always recommend that gardeners mix a little natural topsoil into their raised beds. The addition of a little natural mineral soil will increase the longevity of the mix. Be sure to supplement with a fertilizer formulated for vegetable plantings.

When determining how the amount of raised bed growing mix to add to your beds, use this formula:

Soil Application Formula

([area to cover] ft² x [depth in inches desired] x 0.0031 = ___ yd³).

Example: If you wanted to cover a 20 square foot area with 2 inches of compost, the result would be: 20 ft² x 2 inches of compost x 0.0031 = 2.48 yd³.

(Click here for a full overview of how to prep a new vegetable garden from start to finish.)

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Can I Grow Plants in Pure Compost?

“I have some large compost bins, which produce a lot of compost. Can I plant things in pure compost, or do I need some “dirt” with inorganic materials for the best results? How much inorganic material do I need?” Question from Naomi or Oakdale, California

Answer: Congratulations on your composting success! Compost is one of the best garden amendments available. You can plant in straight compost, but I suggest incorporating it into your sandy garden soil or mixing it with other additives if you want to use it for container plantings.

Compost as a Garden Amendment

When using compost to fortify gardens, incorporate it evenly into your natural soil. Add it liberally if your soil is of very poor quality–especially if you want to grow crops that need fertile soil, like fruits and vegetables. You might also consider building raised beds to make the most of your compost bounty.

Compost as a Potting Mix Additive

If you plan to use your compost for container plantings, include other additives to encourage better root growth in the long term. These include Black Gold Canadian Sphagnum Peat Moss, perlite, and vermiculite. The peat moss with lighten the mix and give it more structure and porosity, while the perlite will help increase drainage. Vermiculite holds water, adds porosity, and holds and distributes nutrients. A well-rounded potting mix would include 40% compost, 30% peat moss, 20% perlite, and 10% vermiculite.

I hope that this helps, and keep composting!

Jessie Keith

Black Gold Horticulturist

Do Livestock Troughs Make Good Raised Beds?

“Do livestock watering troughs make good vegetable garden raised beds?” Question from Sandy of Chester, Virginia

Answer: Yes! Livestock troughs make excellent raised beds. Choose deeper troughs. Those that are 2-feet deep are best. More depth helps them better support larger and deeper rooting vegetables.

The key is making sure that they have good bottom drainage, so be sure to drill/punch plenty of holes at the base to ensure water drains all the way through. You will need an inch or half inch hole every foot or so. Smaller holes are likely to get plugged up. (Look for metal-cutting drill attachments.)

For best veggie production, fill your trough beds with an excellent growing mix and fortify it with fertilizer formulated for vegetable growing. Our compost blend and natural and organic potting mix are great for raised beds! I also recommend that you plant compact vegetables ideal for container growing. (Click here to learn more about the best miniature vegetables for containers.)

Happy gardening!

Jessie Keith

Black Gold Horticulturist

Raised Bed Soil Enrichment

Organic matter will greatly increase the water-holding ability of any soil. (Image by Jessie Keith)

“What can I incorporate in my soil on an elevated bed to help retain moisture? It’s very hard to keep soil moist.” Question by David of Brookville, Ohio

Answer: Organic matter, organic matter, organic matter! Amendments rich in organic matter have high water holding ability and keep soil porous to create the best possible environment for root development. Amendments with excellent water-holding capacity include compost, peat moss, coconut coir, and earthworm castings. (Check out Black Gold’s suite of OMRI Listed soil amendments for organic gardening.) Add products such as these to your raised beds in the beginning of the season at a 2:1 ratio of amendment to soil. Then mulch with a thick layer of compost or straw to keep weeds down and further hold water. If you do this, your beds will hold water really well!

Happy Gardening! Jessie

Raised Beds: Respecting the Law of Return

To enrich a full raised bed, use low volume, high potency organic fertilizers before planting time in early spring.

If you’re growing vegetables in raised beds, you must respect the Law of Return. This law states that nutrients extracted from the soil by growing plants must be compensated for by tilling their dead remnants back into the soil or fertility loss will result. Because plants are often grown more densely in small or raised beds, proportionately more nutrition is drawn from the soil each year than in in-ground gardens. The chances of running a deficit are very real, and your plants will show it, but by then it’s too late.

The challenge of raised beds is that there’s no room for adding gobs of compost to the box because it was filled to the top in the first place. The fertility of all raised beds will decline each year unless you return it with fertilizer to compensate for these losses.

Add Organic Matter

High-density gardening in raised beds draws proportionately more nutrition from the soil over the course of each season.

To keep microbe populations high, organic matter is needed. If your potting soil is decomposing so the soil level has dropped, can you refill it with any of the Black Gold potting soils with RESiLIENCE® or just use Black Gold Garden Compost and work it into the old stuff. But if your soil mass is maxed out, use fertilizers that provide higher levels of nutrition without much volume. Older soilless mixes can also acidify, which will inhibit plants from taking in needed nutrients while reducing soil microbes and overall soil health. A simple soil pH test should be conducted to determine soil acidity/alkalinity. To return acid soils to a neutral ph is ideal, a liming agent is required.

Fertilize

Organic fertilizers are slower to become available to plants than synthetics, so preparing your raised bed soil well in advance of planting time. Fall is ideal, but early spring works just as well. This allows time for the various raw materials to decompose, interact and create the synergy between plants, microbes, and earth to give your garden everything it needs, naturally.

For gardens where there’s little space, two organic fertilizers offer everything needed to fuel this year’s vegetable crops. They’re like ordering a la carte or choosing a combination plate at a Mexican restaurant. The combination is a tomato & vegetable fertilizer with added alfalfa meal.

An organic tomato & vegetable fertilizer, with a balanced ratio of nitrogen, phosphorus, and potassium should be added. Estimate at least one bag of fertilizer for each 4′ by 8′ raised bed to calculate how much you need.

Rose growers have always been keen on using alfalfa Meal a la carte, which contains about 3% nitrogen plus other benefits. What makes it doubly valuable is that alfalfa is a legume, a nitrogen-fixing plant, so all of its remnants from baled hay to this byproduct of milling also contain vestiges of the mycorrhizae, unique fungi that live symbiotically within these plants.

To apply these fertilizers, spade up your raised bed with a fork to open it up a foot or so deep, then sprinkle the fertilizers evenly over the soil. Let them filter down into the nooks and crannies, then spade over each bed again to help the soil tighten around the fertilizer. Once thoroughly blended, rake the surface smooth so it’s ready to plant. Water deeply, if there has not been sufficient rain.

The Law of Return

The longer the garden sits after you’ve returned nutrients to the soil, the more fertile it becomes. As temperatures warm, microbes activate and enrich the soil further. So when it’s time to plant your peas in March, and anything else after that, complying with the Law Of Return will guarantee you vegetables show their appreciation with the most generous harvests you can imagine.

Raised Bed Rotation and Rejuvination

Raised Bed - Mike Darcy — All raised beds require crop rotation and soil replenishment to avoid the accumulation of soil-borne pests and diseases.

Mothers always admonish us “not to hang out the dirty laundry”, which is code speak for keeping unpleasant family secrets out of neighborhood gossip. This same problem is afflicting the raised bed garden world where nobody wants to hear the downside of these tiny plots of food plants. At the heart of it is the very old concept of crop rotation. Even the ancients knew that crops grown in the same place year after year developed big problems without rotation.

Why Rotate Crops?

The science is quite simple because diseases and pests can accumulate every year you cultivate a small vegetable garden. It may not be visible the first or even the second year, but by year three it can strike with a vengeance. This is how long it takes for your soil to foster a killer dose of pests and pathogens.

Imagine a 4-foot-by-8-foot planting area (the size of a typical raised bed) that you grow tomatoes in year after year. A mature tomato can occupy half that square footage, with its roots fanning out over the area underground. To properly rotate your crops, you must not grow tomatoes in the same place you did the previous year. In this case, the only choice is to plant on the opposite end of the raised bed. That leaves only two possible spots for the tomatoes.

Farmers know to rotate their fields over four years to ensure healthy crops. That’s four entirely different growing areas for crops in the course of four years; three years with the crop being grown in a different spot and a fourth year for a given growing area to lay fallow to “rest”. But farmers have space for rotation. What about home gardeners working within the confines to small raised beds? Without sufficient space for rotation, the results can be devastating.

nematodes 062 — You cannot miss the damage caused by root knot nematodes. Roots appear swollen and distorted.

For example, a microscopic pest called root-knot nematode often strikes when tomatoes are grown in the same location or very close-by year after year. This pest is invisible to the eye and is common to most soils but present in such small numbers that it doesn’t cause serious problems. But when tomato crops are not rotated, these nematodes multiply to fatal proportions. As a result, tomato plants begin to turn yellow and die because too many nematodes have invaded their roots. No matter how much you water or fertilize, nothing will change this downward spiral.

You won’t know the cause until you pull up an ailing or recently deceased plant to see first hand what the roots look like. Root-knot-nematode-infected roots look bizarrely knotted and swollen and are obviously unable to support the plant. As tomato fruits mature and heat stimulates growth, the plants can’t keep up. There is no cure for badly infected plants, and fear of this organism is why gardeners often plant big African marigolds (Tagetes erecta) around food plants because it is known to discourages nematode populations.

Replace Old Soil

Rotation is key, but soil replacement can also work wonders towards keeping raised bed problems at bay. Replacing your garden or potting soil with fresh every other year will help discourage the accumulation of diseases and pests, such as the root-knot nematode. Quality garden soil like Black Gold Garden Soil is rich, fertile, and fresh. It reduces the need to rotate crops, will fortify your garden to increase yields, and rid your raised bed of “dirty laundry” that could mean the downfall of your summer garden plantings.

The more cautious your are about ensuring healthy soil for your raised garden, the better. For example, if you move into a new home with an existing raised garden, it’s best to assume its potting soil is nutritionally exhausted and that crop rotation has not occurred. Plus, it’s just a good idea to replace the soil anyway because the removal process may give you clues to other problems, like drainage or the presence of aggressive underground grass roots. Excavation will help you discover if there are problems lurking below.

Small gardens don’t have to be hotbeds of pests and diseases, if you know how to compensate with rotation and garden soil replenishment. Rotate your crops liberally (preferably on a 4-year cycle), replace old, spent soil, and reap the harvest!

Edible Gardening Everywhere in the Garden

Freeman Garden raised beds for Darcy — My neighbor Ron removed a large section of his front lawn and created an attractive series of raised beds for vegetable gardening.

It was not very many years ago when gardeners had distinct areas for vegetables and flowers. There was a vegetable garden and a flower garden and the two did not mix. In addition to those two distinct areas for vegetables and flowers, if a gardener grew roses they had another bed that was exclusively for roses. But this is changing. Now edible gardening can be everywhere!

vertical window garden — This vertical garden from an old window frame has landscape fabric pockets in which herbs were planted.

Mixing Ornamentals and Edibles

The times have changed in many ways regarding how people garden, and now it is often more of a mix with vegetables and ornamentals planted together. With home lots becoming smaller, plant breeders have realized they need to change the scope of the plants they release to home gardeners. New edible plants have even been developed especially for container gardening and small space areas. This is exactly what many homeowners need.

When I talk to other gardeners and visit other gardens, I notice a huge increase in the growing of vegetables. People are concerned about pesticides on what they eat and there is also a heightened interest in environmental issues, such as where something was grown and how transportation enters into the picture. Growing local has certainly been a phrase that has new meaning and is now in everyday vocabulary.

In my own neighborhood, gardeners have reduced or even eliminated the space devoted to lawns and have often converted it into vegetable gardens with ornamental plantings as well. My neighbor Ron removed a large section of his front lawn and created a series of raised beds for vegetable gardening.

BRAZELBERRIES raspberry shortcake in square terra cotta pot — Brazelberries Raspberry Shortcake grows beautifully in ample containers.

Raised beds can create an environment in which the homeowner can control the soil for optimum harvest results. Many of us have spaces where the soil is not conducive to vegetable gardening but by amending it in a raised bed, the right growing conditions can be obtained. This can be an easy fix with buying good topsoil and adding Black Gold Garden Compost Blend along with a good fertilizer formulated for vegetables. A new gardening space is thus instantly created. In neighbor Ron’s garden, due to an ever present deer problem, he also built a fence around the raised beds and then espaliered apple trees on the fence wires.

Edibles in Containers

There has been a noticeable increase in vegetables and berries for containers. It was not long ago that I had never or rarely seen vegetables or berries growing in containers. Containers were meant for growing flowers! In 2012, with the introduction of BrazelBerries®, all of a sudden there was a series of different berries that were bred specifically for growing in containers. Container gardening reached a new level with the blending of berries and flowers. Raspberry Shortcake™ is a dwarf and thornless raspberry that is ideal for growing in containers. For those with a deck or balcony, they could now grow their own raspberries. Jelly Bean™ is a super dwarf and hardy

blueberry that is also easily grown in a container. It provides almost year round color with the typical white blueberry flowers in spring and the bright green leaves in early spring that become darker shades of greens and reds as the season progresses. The berries are large-sized and appear in mid-summer. Both of these berries would benefit from using Black Gold Natural & Organic Potting Soil in the container.

Gardeners are very innovative and my neighbor, Janet, attached a wooden planter to the railing on her deck and planted lettuce. She said it was a delight to be able to walk out from her kitchen onto the deck and cut lettuce for salad. In another garden that I visited, a vertical garden from an old window frame had been created with landscape fabric used to create pockets in which herbs were planted. Black Gold Natural & Organics Potting Soil would be ideal for both of these conditions.

There are no rules to mixing up berries, vegetables and flowers. Be aware of the environmental conditions as most vegetables need full sun or at least six hours per day. Also, remember that since these plants are in containers, they will tend to dry out on sunny and windy days so be aware of moisture needs.

Check out your local garden center and you might be pleasantly surprised at what is available for even small spaces. You can not only enjoy your plants but in many cases can reap the harvest.

Nerd Night Lettuce — My neighbor Janet attached a wooden planter to the railing on her deck and planted beautiful, fresh lettuce.

Articles

“What soil is best to use for my herbs in a raised bed? I have lemon balm, mint, basil, and thyme.” Stacey of Brooklyn Park, Minnesota

How to find soil volume for square or rectangular raised beds:

Pros of Raised Bed Gardening

Cons of Raised Bed Gardening

Raised Bed Covers

Soil Application Formula

Soil Application Formula

([area to cover] ft2 x [depth in inches desired] x 0.0031 = ___ yd3).

Example: If you wanted to cover a 20 square foot area with 2 inches of compost, the result would be: 20 ft2 x 2 inches of compost x 0.0031 = 2.48 yd3.

Compost as a Garden Amendment

Compost as a Potting Mix Additive

Add Organic Matter

Fertilize

The Law of Return

Why Rotate Crops?

Replace Old Soil

Mixing Ornamentals and Edibles

Raised Beds

Edibles in Containers

([area to cover] ft² x [depth in inches desired] x 0.0031 = ___ yd³).

Example: If you wanted to cover a 20 square foot area with 2 inches of compost, the result would be: 20 ft² x 2 inches of compost x 0.0031 = 2.48 yd³.