Category Archives: Edible Gardening

Caring for Your Vegetable Plants

With the vegetable gardening season in full swing, we checked in with our Nursery Manager Barb Pierson to get some helpful tips on caring for edibles plants to encourage plant health and maximum yields. Here’s her advice:

1a
Early Summer in White Flower Farm’s Kitchen Garden

Watering

In general, with tomatoes and most other edibles, you want to water the soil, not the plant. “You’re also supposed to do it in the morning,” Pierson says, because that allows any leaves that do get wet to dry in the sun during the day, but not all of us have time to get the watering done in the morning so, if need be, do your watering later in the day, being careful to keep the foliage as dry as possible.

“If you have drip irrigation, do not run it all day, every day,” Pierson says. The flavor of tomatoes is vastly improved by letting the soil dry out a bit. If you keep the hose going, “you’ll have water bombs instead,” Pierson says. “A little bit of flagging in the plants is OK. They get a silvery color, and they start to droop just a little bit.” That’s when you water.

TOMATOES

pruning tomato growth
Pruning Tomato Growth

Pruning

“Everybody does something different,” Pierson says. Once, on a visit to a local botanic garden, Pierson saw tomato plants that “didn’t have a leaf left on them,” she laughs. “I said [to the staff], ‘What are you doing to these plants?’ They told me the fruit is better if it’s not shaded, but I’ve never found that to be true.”

This is what good tomato hygiene looks like. The base of the stem is free of leaves and suckers.
This is what good tomato hygiene looks like. The base of the stem is free of leaves and suckers.

The important thing, Pierson says, is to practice good tomato hygiene, removing leaves that are touching the ground to prevent soil from splashing up onto the foliage and possibly conveying diseases. This is particularly important if you’ve had disease problems in the past, she says.

As you snip off leaves, be careful to leave a stub of about ½”. This prevents cutting into the main stem, which is something that hurts the plant and can open it, literally, to problems.

3. pinching away foliage -- especially leaves and suckers that are close to the ground. Removing these helps%
Pinching away foliage — especially leaves and suckers that are close to the ground.

Higher up on the plants, “you can thin the plant for better air circulation, which helps with fungal problems,” Pierson says. “Cut some leaves and non-fruiting branches.” If it’s a rainy summer, the need to promote air circulation is particularly important.

Pierson occasionally prunes to control the size of indeterminate tomato plants (the varieties that tend to sprawl all over the place). “When your ‘Sungold’ is 8 feet tall, you’re going to lop it,” she says. “For purposes of supporting the plant, you might also prune it.” But topping a tomato plant may mean you’ll lose some fruit, so think twice before you make a cut. “Any time you prune the plant, you’re possibly reducing production,” she says.

Feeding

At her house, Pierson plants most of her tomatoes in container pots, using a mix of 2/3 potting mix and 1/3 compost. “That’s heavy to compost,” she says. When she plants them in raised beds or garden beds at the farm, she also prepares the soil before planting by working in lobster compost, which helps condition the soil while adding vital nutrients. [To see our recent post on adding nutrients to the soil before planting tomatoes, scroll down.]

If you’ve amended your soil properly before planting, feeding your plants with fertilizer is optional. “The compost is doing most of the work,” Pierson says.

If you haven’t amended your soil, or even if you have and would like to give your tomato plants an extra helping of nutrients, you can use fertilizer for what Pierson calls “a boost that will help get heirlooms and cherries into fruit and flower sooner.”

In areas of the country with a short growing season, this is especially important.

Choosing which fertilizer to use depends on your preferences and your growing conditions. Pierson has always relied on White Flower Farm’s All-Bloom Fertilizer, a 15-30-15 formula that’s high in phosphorus for root growth, and micronutrients. One of the bonuses is it won’t attract critters the way fertilizers that smell like fish sometimes do. The key here is trial and error to see what works best in your garden.

Fertilizer helps promote “more fruit set and earlier fruit set,” Pierson says.

Pierson lets tomato plants grow in the ground or in container pots for approximately 3 weeks before feeding them for the first time. Then she’ll feed roughly 2 to 3 more times before the plant is actually producing. “When the plant sets its fruit, back off feeding,” she says. “Back off water and back off feeding once the plant is covered in fruit. Too much water, and your cherry tomatoes will be cracking.” Excess water also invites diseases.

“Never feed after mid-August,” Pierson says, because it’s the equivalent of offering someone caffeine before bedtime. At that time of year, “the plants are sensing the shortened day length. They honestly don’t need anything else.”

Pests & Diseases

Septoria Leaf Spot of Tomato Photo courtesy of Missouri Botanical Garden
Septoria Leaf Spot of Tomato. Photo courtesy of Missouri Botanical Garden.

Septoria

A fungus that manifests itself as brown spots on leaves, Septoria is one of the most common conditions that can afflict tomato plants. It begins on the lower leaves and spreads upward. “If you’ve had septoria in the past, when the plant gets to be 24” tall, remove all foliage that’s touching the ground,” Pierson says. This prevents soil from splashing up onto the leaves and possibly introducing diseases.

For more detailed information, visit the excellent Missouri Botanical Garden website here.

Blossom end rot, photo courtesy of Missouri Botanical Garden
Blossom end rot, photo courtesy of Missouri Botanical Garden

Blossom End Rot

These brown spots at the base of tomatoes may indicate a calcium deficiency. “Calcium can be there in the soil and be unavailable because of soil pH,” Pierson says. “If you have a history of having blossom end rot, make sure you’re making the calcium available. It means the soil is too acid, so put in granular lime in a feed-the-chickens kind of manner [or what amounts to a couple of tablespoons].”

Other problems, including the moisture level of the soil and improper or excessive fertilization, also may cause blossom end rot.

For more information, click here.

hornworm_covered-in-the-cocoons-of-a-parasitical-wasp_Photo-by-Barb-Pierson
Hornworm covered in the cocoons of a parasitical wasp. Photo by Barb Pierson.

Hornworms

“If you see a branch with no leaves, it’s probably hornworms,” Pierson says. The bright green, chubby insects are sometimes hard to spot because they blend in so well with tomato stems and foliage, but the worms have diagonal white stripes on their sides and a spiked horn near their tail ends (hence the name). To rid tomato, eggplant, and pepper plants of these foragers, “just pick them off,” Pierson says. You don’t want to spray or use chemicals because you’ll be eating food from these plants.

If you see a hornworm covered in what appear to be tiny white specks, those are the white cocoons of the parasitic braconid wasp, which eventually kill their host.

For more information, click here.

CUCUMBERS

“Cucumbers are water hogs,” Pierson says. “If it’s hot and dry, you’ve got to water.” Apart from that, cukes require very little maintenance. “Let them climb,” Pierson says. Pick the fruit, and when the plants subside, generally in the high heat of August, “just pull them out.”

SQUASH

A host of plants, from Phlox to Lilac, are susceptible to powdery mildew. Squash is another. Pierson recommends the “old-time” milk treatment, which involves diluting 1 part milk (any type from whole to skim) in 2–3 parts water and spraying it on the plant until the leaves are dripping. “It changes the pH of the leaf so it’s not as favorable for the powdery mildew to spread. Do it preventatively and then once per week. Reapply after it rains.” Pierson confesses that she doesn’t bother with the milk treatment because the squash fruits are fine regardless of the mildew. The milk treatment “comes under the heading ‘Too Much Work,’” she laughs.

quash-vine-borer_Photo-courtesy-of-Missouri-Botanical-Garden.
Squash vine borer. Photo courtesy of Missouri Botanical Garden.

Squash borers are another story. “The borers will work their way into stems and small fruits, and start to grow. The squash turns brownish, and it will fall off and die,” Pierson says. The remedy? While there are a few measures that can be taken to stop the borers, most are tedious and time-consuming. Barring the use of chemicals on your edibles, you might prefer to pull the plants, disposing of them completely (do not compost) and leaving the soil open to birds who will help clean it.

For more information, click here.

LETTUCE

Keep cutting lettuce for a “cut-and-come-again harvest to avoid early bolting,” Pierson says. Lettuce generally won’t bolt “unless it gets super hot. If it bolts, remove it, and plant fresh seed. You’ll have good lettuce in the fall if you re-seed in mid-August.”

EGGPLANT & PEPPERS

Eggplant and Peppers require little maintenance, perhaps just some staking as their branches, laded with fruit, get heavy.

One tip for next year: both eggplant and peppers “love to be planted in the collapsible potato bags,” Pierson says. The black bags get warm in the sun, making the soil warmer than it is in most garden beds. “They like hot roots,” she says.

Amending Your Soil to Maximize Tomato Harvest

One day's tomato harvest, rinsed and ready for cooking and freezing
Some of the fruits of our colleague’s 2015 tomato harvest, rinsed and ready for cooking and freezing.

When it comes to growing tomatoes, it seems every gardener has an opinion about how to get the biggest and best harvest. A recent staff discussion focused on techniques for amending the soil prior to planting tomatoes. The idea is to give the plants all the nutrients they need to produce a bumper crop of tasty fruits, a practice that’s particularly important for gardeners whose plots are smaller in scale or whose properties make it difficult to rotate planting beds.

Last year, one of our staff members did a good deal of poking around on the Web, which, while sometimes a hazardous pursuit, inspired her to try some traditional but more recently underused ideas. She decided to take a few chances with amendments that are more common to the kitchen waste bin or compost heap than the nearest big box store. The result? She enjoyed her highest yields ever on a varied crop of tomatoes that ran the gamut from cherries and paste tomatoes to slicers and beefsteaks. She feasted on salads, BLTs, gazpacho, and stuffed tomatoes all summer and still had plenty of beautiful, ripe fruits for making sauce and roasting tomato wedges with basil (for a bruschetta topping). She froze chopped tomatoes to use in soups and chili recipes, and froze tomato sauce, as well as the aforementioned bruschetta topping. (We’ll be running these recipes later in the season.) Needless to say, she made some of us a little jealous with her wintertime lunches. Determined to enjoy similar results and to share her rediscovered techniques with you, we ran her list of amendments by our nursery manager Barb Pierson, another champion tomato grower. Pierson applauded some of our adventurous colleague’s amendments but voiced concerns about others. What to do? We thought it best to set it all down, and let you make your own decisions based on circumstances in your own backyard.

We start by digging holes about 15in deep
To begin amending the soil, start by digging holes about 15 inches deep (this is not your planting depth, but the space you’ll need for adding amendments).

Soil Amendments Used Successfully by Our Adventurous Colleague

Since Tomato plants are deep-rooted heavy feeders and thrive in highly organic soils, the ground must be well prepared with nutrients to sustain them throughout the growing season, optimizing growth and fruit development. Everyone has their own recipe for improving soil with organic matter, but here’s what our adventurous colleague tried with great results:

She dug deep holes (at least 15” deep, if possible. Note: this is not the depth for planting a tomato but rather it’s a hole deep enough to accommodate the amendments before planting). Into the hole, she added the following:

Fish
Fish heads, fish fillets from the supermarket freezer section, or a handful of fish and kelp meal help boost soil nutrients.
  • Fish heads (or frozen fish fillets, if you can’t get fish heads): Put 1 fish head or the equivalent in the bottom of each hole. You also can add a handful of fish and kelp meal to help boost the nutrients.
eggshells
As winter shows signs of coming to an end, we begin collecting eggshells. Just rinse them and keep them a bowl in the refrigerator or in a protected outdoor space. Before adding to the soil, crush them with a potato masher or with your hands.
  • Crushed eggshells: These add calcium to prevent blossom end rot. Throw a couple of handfuls in each hole.
bone meal
Here we add a handful of bone meal.
  • Bone meal: This promotes strong root growth and abundant blooms. Add a handful to each hole.
Compost and composted manure
Compost and composted manure are great additions to the soil for tomatoes and lots of other plants. Compost adds basic nutrients and improves soil structure. Composted manure provides nutrients all season long.
  • Composted manure: This provides a slow release of nutrients over the growing season. Add a couple of handfuls to each hole.
  • Compost: It will add basic nutrients and improve soil structure so the soil drains well yet retains some moisture. Add 2-3 handfuls in each hole.
Combine all the ingredients, and mix!
Combine all the ingredients, and mix!

Please note that the 15” hole will be partially filled with the amendments, which should then be partially buried by some of the soil in your garden (think of the hole as a big mixing bowl). This process of amending can be done prior to planting your tomatoes when the soil temperature is still on the cool side.

Pierson does not recommend fish heads or bone meal because “they would attract critters and most likely your plant will be dug up.” (It should be noted that a family of raccoons in the neighborhood of our adventurous colleague left her tomato plants alone, but depending on how many critters live in your area and how well your vegetable garden is fenced, you may wish to select and tailor your amendments accordingly.)

Pierson agrees that compost and eggshells add beneficial nutrients to the soil, but she isn’t sure the quantity of eggshells noted above would be enough to provide calcium throughout the season. Perhaps the thinking should be that that every little bit helps.

Pierson ends by saying, “Preparing the soil should focus on: Did you have problems the previous season? And practicing good sanitation [i.e. disposing of plants and clearing the garden beds] at the end of the season so that disease issues don’t start again. Moving your garden location is essential if problems were severe.”

But the main thing Pierson stresses for successful tomato harvest is soil texture. “Soil texture is important – turning the soil, adding high quality potting mix and focusing on drainage are very important. Roots need air to breath and to take up nutrients, compost creates air pockets in the soil. Having a light well-drained soil is the most important thing.”

So there you have it. An array of options, some or all of which are bound to improve your tomato yield. Our best advice is to take into account the conditions in your backyard and vegetable patch, and choose the amendments that work best for you. Some trial and error may be required, but that’s just the way things go in a garden. As Pierson put it, “I like the idea of trying things, that is what growing is all about. There are no right or wrong answers, only what works for you in your particular environment.”

Harvest Fresh Fruits & Vegetables From Pots on Your Patio

By Barb Pierson, Nursery Manager

lettuce as container gardens
The options for container pot edible gardening were once limited mainly to salad greens and herbs, but there is now a wide variety of plants that thrive in pots and smaller garden spaces.

For gardeners with limited outdoor space or the desire to harvest fresh fruits and vegetables a few steps from the door, container pot gardening is a great way to go. While the options for container pot edible gardening were once limited mainly to salad greens and herbs, there is now a wide variety of plants – from Tomato varieties to Peppers and Eggplants – that thrive in pots and smaller garden spaces.

Growing vegetables in containers can be done in any location that has 6-8 hours of sun per day.

The benefits are obvious: There’s no need to dig and prepare a garden bed. Gardeners enjoy easy access to the pots for watering, fertilizing and harvesting. Containers can be moved to suit the needs of the plants or the gardeners. And, best of all, there’s no weeding.

There are a few obvious drawbacks: Some varieties of vegetables such as large pumpkins cannot be grown in containers. And more water and fertilizer is needed to produce a good harvest in a container. But the extra bit of effort is worth the reward of a delicious harvest.

To start a container garden of edibles, here are 9 steps to get you started:

Barb with pots
Keep in mind that the pot or pots you select must be large enough to hold soil and the roots of whatever plant or plants you wish to grow.

1. Choose Your Pot

Keep in mind that the pot or pots you select must be large enough to hold soil and the roots of whatever plant or plants you wish to grow. Tomatoes and vining crops produce best in containers that are at least 20–22” in diameter. Peppers can go a little less at 16” diameter. Greens such as Lettuce prefer a broad flat pot such as a large bowl-shaped container.

Drainage is imperative! Make certain that each pot has several holes in the bottom. It is NOT necessary to put stones in the bottom of the pot.

As long as there is drainage, pots made of almost any type of material will work. Fiber pots work well but are not decorative. There are many plastic pots that are decorative, functional, and lightweight. I prefer something that’s easy to move and to empty at the end of the season.

bags of compost
Use a lightweight, high quality potting soil and mix it at 2/3 potting soil to 1/3 compost.

2. Soil

Use a lightweight, high quality potting soil. Never try and use garden soil from your yard. After you have purchased your potting soil, mix it at 2/3 potting soil to 1/3 compost. This mixture allows the plants to retain moisture and nutrients. Types of compost can include: leaf mold compost you have made, dried aged manure, or shrimp and seaweed compost. I create a mix in a wheelbarrow or garden trug. Lightly water the mixture before placing it in your pot so the peat moss in the mix isn’t too dry.

When filling your container, firm in the soil without compacting it too much.  Unpot your vegetable plant and place it in the center, if you wish, or spaced with other plants if you’re creating a combination. Add more of your container mix, pressing down gently and adding more soil until the pot is filled to about 2-3” below the lip. Always leave space at the top to create a watering reservoir.

3. Planting Depth

This is key. For Tomatoes, remove the lower leaves and plant the Tomato deep in the soil. Roots will form along the stem. (The only exception is Grafted Tomatoes, which should not be set in soil below the graft line, which is generally marked with a tie or piece of tape.)

For Cucumbers, Squash, Lettuce, Eggplant and most other vegetable starts, plant at soil level.

Tomato cage
Pepper ladders (shown here) or Tomato cages can be used to support smaller Tomato plants, Peppers and Cucumbers.

4. Support

Tomato cages can be used for smaller Tomato plants, Peppers and Cucumbers. Cone or pyramid-shaped trellises usually work better than flat types. Chicken wire can be bent and used to make a cage. A few stakes can be placed around the perimeter of the pot to form a teepee.

Pot platforms or deck protectors can be used to move your pots around, protect your patio or deck, and allow air to circulate and water to drain from the pots.

5. Watering

Container plants in full sun need to be checked every day. Using organic compost will help reduce the need, but the hot sun will require that you check your plants daily. The best way to see if your plants need water is to stick your finger in the soil. If it’s dry to the touch below the surface ½” or so, it’s time to water. Learning to see signs of wilting is something that will happen as you grow plants every season. Look for the plants to be flagging a bit, or for the soil to begin separating from the sides of the container. Those are signs your plant needs water. But overwatering can also be a problem, in particular for Tomatoes and Peppers, so make sure you observe carefully and do not water during cloudy or rainy weather unless you see that the soil is dry under the surface.

Tomatoes and Peppers need regular watering and feeding while they’re growing, but when the fruit starts to mature, it’s important not to overwater or over-fertilize as this will cause your fruit to be susceptible to disease and reduce the flavor.

6. Fertilization

After the vegetables have settled into their new pots and new growth can be seen, it’s time to fertilize your plants. If your potting soil has slow-release fertilizer, you should wait at least several weeks before adding more. Use fertilizer at the rates recommended on the label. There are many organic and synthetic fertilizers on the market, and some of them specifically are for vegetables. If you use a fertilizer that is higher in phosphorus than nitrogen and potassium, it will promote more fruit. Read the labels carefully and apply what’s recommended regularly – in particular if you are watering often and the plants are actively growing prior to harvesting, make sure you are feeding. Hot sun and frequent water will leach out valuable nutrients.

7. Staking, Tying and Pinching

Stakes should be inserted into your containers at planting time. As the vegetables grow and produce fruit, tie the large branches so they have support but aren’t girdled.

To fully understand Tomato pruning, visit the Fine Gardening magazine website, www.FineGardening.com, and enter “tomato pruning.” They offer a detailed explanation of the process.

8. Insects and Disease

Prevention is the best organic method of pest control. Proper watering techniques avoid most issues with vegetables and herbs. Fertilization, full sun and air circulation are also imperative. If you do have insects or disease, use organic control measures such as horticultural oil and insecticidal soap.

9. Harvesting

Each type of vegetable has specific harvesting techniques. For Tomatoes, allow them to ripen to their mature color and feel the fruit to make sure it has soft give to it. Some varieties twist off easily when they are ready to be picked. Know the mature color and age, and resist the urge to pick too early!!

 

FAVORITE HERBS FOR CONTAINERS

pots on roof
Many herbs, such as Mint, Thyme, Oregano, Sage and Rosemary do well in containers.

Mint

Always plant Mints in pots! It’s very invasive in the garden, but so good for drinks and as a garnish. Plant in large pots with plenty of soil depth. Mint needs quite a bit of water so make sure you check it and add compost to the potting mix for better water retention.

Thyme

Thyme is pretty and creeping so it cascades nicely over the rim of a pot. Use a shallow container because Thyme has a fine root system and is prone to root rot when given too much soil.

Parsley

Cut Parsley often to keep it from flowering or “bolting.” (If it does bolt, it tastes terrible.) It’s best planted in a large pot.

Sage

It can easily be overwatered so plant it in a container that is medium depth or shallow and has good drainage. To promote drier conditions, don’t add too much compost.

Oregano

Delicious and aromatic, this is a fairly aggressive grower so use a large pot and treat it like Mint.

Rosemary

This favorite can be quite tricky when it comes to watering. Too much water, and it’s unhappy, not enough and it’s equally unhappy. Take care when combining it in a mixed container and be sure you have good drainage!!

 

FAVORITE TOMATOES FOR CONTAINER POTS

Note: Many of these are compact or “determinate” varieties. The latter means they have a neater habit than “indeterminant” Tomatoes, which tend to sprawl and require more support.

grow bag, pepper mini red bell sweet
Many compact or dwarf varieties of vegetables are ideally suited to smaller quarters, but they can also be planted in small spaces in vegetable gardens.

FAVORITE VEGETABLES FOR CONTAINERS

Note: Many of these are compact or dwarf varieties that are ideally suited to smaller quarters. They also can be planted in small spaces in vegetable gardens.

Brazelberries
There are several varieties of BrazelBerries® compact berry bushes such as Peach Sorbet™ that do well in containers.

FAVORITE FRUITS FOR CONTAINER POTS