Growing onions

Although onions can be grown from seeds, sets, or transplants, I prefer to grow them from seeds. After a cold winter, the arrival of seed catalogs and the starting of onions seeds remind me that spring is around the corner. I like to watch the seeds germinate and sprout long leaves which need to be cut 2-3 times before transplanting. I also like detangling the roots of the seedlings when it is time to transplant them in the spring. To me, onions = spring.

As an experiment, I planted Walla Walla onion seedlings last November. I read that planting sweet onions in the fall results in a sweeter onion. What I did not know was that the onions would be larger and mature much earlier than those planted in the spring. So, this November I will be planting even more onions to overwinter!

While I am already enjoying the Walla Walla onions (over 1 lb each!) I planted last fall, I have noticed that the onions I planted this spring are starting to bulb up nicely. I anticipate the rest of the onions being ready to harvest around the end of July.

Onion showing symptoms
of Pantoea ananatis

This week, I came across one sweet onion (Candy) that had suddenly looked kind of weird. The onion was bulbing up like the others, but it had floppy white/bleached looking center leaves (the outer leaves were green and healthy looking). Having seen what happens to tomato plants if disease is not controlled early, I ripped this onion out of the ground and started my investigation into what was the cause of the wilt. 

It turns out that the onion was likely infected with a bacterial disease caused by Pantoea ananatis. This bacterium causes what is called "center rot" and commonly occurs in sweet onions during periods of hot weather. The classical sign of infection is the collapsed bleached center leaves hanging down beside the onion's neck. Bingo! This is exactly what was wrong with my onion.

Go figure: high temperatures are necessary for the development of this disease. We have been in a 90-degree heat wave for about 2 weeks. This is another benefit of growing onions over the winter - they mature earlier, thereby helping to prevent loss from center rot.

I also suspect that the overhead misters I installed on the onion bed may have contributed to the bacterial disease. Water from the misters could be held in the leaf axils making the onion more susceptible to bacteria entering the plant. Needless to say, I have turned off the misters and will rely solely on drip emitters for the rest of the season. 

Tomato leaf spot

Septoria leaf spot infected tomato leaves

About 2 weeks ago, the lower leaves of the some of my cherry tomato plants began to show signs of Septoria leaf spot, an infection caused by the fungus Septoria lycopersici.

While I usually do not see this problem until later in summer, given all the rain we received this month, I am not surprised that it arrived this early in the season. 

Septoria leaf spot is characterize by the formation of numerous small circular lesions that are 1/16-1/8" in diameter. Spots first appear on lower leaves and have a dark brown border and a grayish-white center. 

Heavily infected leaves turn yellow and wither off the trunk of the plant. This can result in sun-scalding of fruit and ultimately a reduction in the amount of fruit produced. 

In an attempt to slow the spread of the fungus, I have had to defoliate all the lower leaves of all my cherry tomato plants. I removed infected leaves using pruning shears (cleaned with a 30% bleach solution before and after each cut). 

Sadly, it looks like I have tomato trees rather than bushy tomato plants. Luckily, none of the fruit show signs of infection. However, I have lost a few clusters of tomatoes due to my heavy pruning of the infected leaves (and not paying attention to where exactly my pruning shears were snipping...oops).

To minimize risk for disease, tomato plants should be:

• Spaced 2 feet apart
• Staked to improve circulation
• Watered early in the day using soaker hoses or drip irrigation to minimize splashing of water onto the leaves
• Grown in a new location in the garden every year

Although I followed all these recommendations, I was not able to prevent Septoria leaf spot from rearing its ugly head. Unfortunately, once this fungus appears, the only thing you can do is control its spread.

Every 7 days (or after rainfall), I will have to treat the infected plants with a copper-based fungicide or a fungicide that contains chlorothalonil. Fungicides will not cure infected leaves, but they will protect new leaves from becoming infected. I will also have to be diligent about removing infected leaves since the disease is spread by wind and water splashing up from the ground and infected leaves.

Cabbage worms

As soon as I see little white butterflies with greyish-brown dots on its wings visit my garden, I know it is time to protect my vegetable garden from cabbage worms.

Cabbage Worm (length = approximately 1")

These butterflies lay hundreds of tiny yellow eggs on the underside of the leaves. The eggs hatch and release velvety green larvae (cabbage worms) that love the taste of broccoli, cabbage, collard greens, and other members of the brassica genus. The larvae feed on the foliage of these vegetables, creating numerous holes. About three weeks after hatching, the cabbage worm form a cocoon-like pupal case. A few days later, a new butterfly emerges and the cycle starts again...and again, throughout the summer. In the fall, these pests overwinter and emerge again in the spring.

Cabbage worms can be very destructive during their short lifespan. Leaves become riddled with small holes, altering the appearance of the plant, reducing yield, and eventually impacting the plant's ability to undergo photosynthesis.

Some gardeners cover their crops with a light floating row cover to prevent the butterflies from laying eggs. This sounds great, but I practice intensive gardening. It is too difficult to cover just the brassica crops. AND, the floating row cover should be applied at transplanting to be the most effective. 

Alternatively, cabbage worms can be hand-picked off the plants. Yeah, this sounds like a lot of fun. Not really! This is a labor-intensive endevour that I know I will not win, so I don't even attempt to fight this battle.

I prefer to use an "organic" control that relies on the bacterium, bacillus thuringiensis (also called "Bt"). Bt can be found at most garden centers under the brand names "Dipel" or "Thuricide".

Although harmless to humans, Bt is toxic to a number of destructive worms upon digestion, including: cabbage worms, tomato hornworms, and cutworms. However, it must be applied when the cabbage worms are actively feeding on the leaves. Once the cabbage worm ingests the Bt, it will stop feeding and die of starvation within 3-5 days.

Since Bt rapidly degrades in the sun, I sprinkle it sparingly over the leaves surface just after the sun goes down in the evening. A bonus: cabbage worms mainly feed at night so the Bt will be most effective at this time as well. Unfortunately, Bt must be reapplied after it rains.

It is possible to still get harvestable ("sellable") produce despite a cabbage worm infestation, provided that it is caught and treated early in the season.

Garlic scapes

Garlic Scapes

Tuesday I harvested the garlic scapes from one of the two varieties of hardneck garlic I planted last fall (Music).

Garlic scapes are the "flower" stalks of hardneck garlic plants. These twisting and twirling stems shoot up from the center of the garlic plant's leaves and signal that the garlic is 3-6 weeks away from being ready to harvest.  

While the scapes do not need to be cut off the plants, some people believe the plants energy will be diverted from forming plump bulbs if the flower was allowed to grow. However, last year I left the scapes on a couple of the garlic plants and did not notice any significant difference between the size or weight of the garlic. So, I do not think it hurts the size of the bulb to the keep the garlic scape on the plant...but why waste such a tasty treat. 

I first noticed the garlic scapes forming about 3 weeks ago. Since it is best to harvest young and tender garlic scapes, I have been keeping a watchful eye on the stalks as they twisted and turned. If I harvest the garlic scapes too early, the scape will continue to grow, making it difficult to remove the nub of new growth. Too late and the scape would be too fiborous to eat. And, you will want to eat them! Garlic scapes have the texture of fresh green beans and taste like mild garlic. They are excellent in salads, stir-fries, and pestos!

Freedom from the hose

Once a garden has been planted, there is nothing more important than water for its ability to survive. 

The best time to water is in the morning (6-9 am) or early evening (5-7 pm), before the sun sets. Since I rather sleep in the morning, I spend my evenings watering each vegetable bed by hand using a hand-held sprinkler.

Not only is overhead watering a waste of water and an invitation for disease, I spend more than 12 hours per week watering all my gardens. Last year I vowed that it was going to be my last year lugging around a garden hose to water the vegetable gardens.

The most economical method for watering vegetable gardens is to use a soaker hose. However, in the past, I found that the soaker hose needed to be on for several hours to provide sufficient water to the roots of each plant. At the time, I really didn't feel that the plants were being watered well enough to encourage a deep root system. 

After considering the alternatives, I decided to install a drip irrigation system. Not only is a drip irrigation system a great time saver, it supplies water directly to the roots of the plants. This minimizes the loss of water due to evaporation and runoff (which occurs with overhead watering) and helps to reduce water bills. An added benefit: direct watering should keep the area between plants dry, which helps limit weed growth. BONUS!

I used the Mister Landscaper Drip Irrigation System (plus additional tubing, emitters, stakes, etc.) for my garden. Setting up the drip irrigation system was easy, but it did require some planning ahead of time. Something I do not usually do when it comes to something like this. 

Ryan efficiently used all the parts to design a simple system while my setup was far more complicated (and messy). I believe my lack of engineering skills showed through in my set up. Nonetheless, after six trips to the big box store to get additional parts, Ryan and I have completed the installation of a drip irrigation system in my vegetable garden. And...IT WORKS! :)

I placed 1 gallon per hour (gph) emitters on all the pepper plants, 2 gph emitters on all the tomato plants, and 10 gph adjustable misters to the rest of the garden (onions, lettuce, beans, etc). I have no idea whether this is the best rate for each plant. I am currently trying to optimize the watering schedule so I do not over or under water each plant. 

Once the system fully operational, it doesn't mean I can just walk away and assume the garden is being properly watered. Periodically throughout the season, I will monitor the soil's moisture level to ensure sufficient water is delivered to the roots of the plants.

Only time will tell whether the investment of the drip irrigation system will pay off. But I am looking forward to the system being a significant time saver for me. I plan to use the my extra time harvesting, weeding, and maintaining my garden, rather than watering.

Alien-like veggie

White/green Kohlrabi

Kohlrabi is a cool weather vegetable and a member of the cabbage family. It is supposed to taste like a cross between turnips and cabbage. 

Although kohlrabi can be directly seeded, I grew mine indoors from seed in early March and then transplanted the seedlings in garden at the end of April.

I have to say, Kohlrabi is probably the oddest-looking vegetable that I have grown in my garden. It forms a swollen bulb-like base that sits just above the surface of the soil. The bulb is either white/green or purple (depending on the variety) and has several leafy stems that protrude randomly from it, giving kohlrabi an alien-like appearance.

It is best to harvest kohlrabi when it is about the size of a baseball (any larger and the bulbs will be woody and have an unpleasant taste). After weeks of watching the bulbs grow, today was the day to harvest one of the eight plants I grew.

I ventured out to the garden, knife in hand, eager to make my first kohlrabi harvest - ever. I sawed at the thick stem to no avail. In the end, I had to rock the plant back and forth to help break up the roots, then I pulled the entire plant straight out of the ground, roots and all. Now I know why kohlrabi is not a common vegetable to grow for the mass markets...it takes more effort to harvest than most vegetables!

I found a recipe for kohlrabi and apple salad on Epicurious.com that I am looking forward to trying this weekend. For now, I wrapped the entire plant in plastic wrap to help secure the leaves and to take up less room in the refrigerator. 

But now I am curious...what does purple kohlrabi taste like?

Peas, Peas, and Peas

Sugar Ann Snap Peas

There are three different types of peas: garden peas, snap peas, and snow peas. The garden pea is the typical vegetable that most people think of when you say "peas". Snap peas have plump pods with full-sized peas. They are often confused with snow peas which have flat and nearly empty pods. Unlike garden peas which require shelling, snap and snow peas can be eaten whole - pods and all.

Peas can be planted as soon as the ground can be worked in early spring (4-6 weeks before the expected last frost). Pea seeds should be directly planted in the ground to avoid damaging their delicate and shallow root system, if transplanted. In early April, I planted two 5 foot rows of Sugar Ann Snap Peas. I spaced the seeds 2 inches apart, and about 1.5 inches deep. 

Sugar Ann is a dwarf variety of snap peas that grows on vines that are a maximum of 2 feet long. Unlike other varieties, these snap peas do not require a trellis for support. However, to make it easier to harvest, I grew mine with a simple trellis made using twine that I had strung horizontally between two stakes. I spaced the twine approximately 5 inches apart vertically for a total of 4 horizontal lines of twine. 

It has been fun to watch these vining plants grow, sending their tendrils up into the air and wrapping around each other and the trellis. 

About a week ago, the snap pea plants had begun to flower. Yesterday, I noticed there was a single snap pea pod that was ready to be picked. One pod? Do I wait for more to grow or pick this one now and eat it without sharing my harvest with others? 

Since snap peas can be picked anytime after the pods form, I decided to wait one more day before picking the first fruits of my labor. 

Today I had my first harvest of snap peas! Although just three pods, it was the perfect amount. I had one for now, one for later, and one to share. Too bad they tasted so good that I ate two myself and only shared one.  

Ping-pong turnips

Hakurei turnips with white flesh

Turnips are a cool-weather crop that is surprisingly cold-hardy. Fall crops are often sweeter and provide for a longer period than spring plantings. This is because the increasing light and heat of the spring and summer triggers turnip plants to produce flowers and seeds instead of new leaves. However, it is possible to harvest sweet turnips in the spring, provided that they are planted early and harvested young (about 2-3 inches in diameter). Older turnips can get tough, pithy, and bitter. 

About 2-3 weeks before my region's last frost, I planted Hakurei turnips directly in the garden by broadcast seeding them between the Walla Walla onions I overwintered last year. This was a great success! Since turnips are fast growing, their dense foliage helped to shade out weeds that would have sprouted up between the onions.

Today I harvested the first batch of spring sown Hakurei turnips. These turnips resemble ping-pong balls. How fun!

Since both the root and leaves are edible, I am on a search for a new tasty recipe to make with the roots and leaves that does not involve bacon grease!

Black gold

I have been busy the last few weeks. I have looking for materials to make "black gold". Black gold is simply compost. Gardeners refer to compost as black gold because it is the best nutrient-rich organic soil amendment one could add to the garden. Plus, it is inexpensive. Compost is made from materials that would have normally been discarded. 

Compost helps to improve plant growth by amending the structure of soil. It helps to break up heavy clay soils and adds water holding capacity to sandy soils. It truly is the secret ingredient to successful gardening!

A combination of "green" and "brown" materials, moisture, and air is used by microorganisms and worms to create compost. 

• Greens = nitrogen rich materials that provide nutrients and moisture for the compost; nitrogen is used by organisms for protein production. Greens are often referred to as the "wet" component of compost.

• Examples: fruit and vegetable scraps, grass clippings, spent coffee grounds, eggshells, young weeds

• Browns = carbon rich materials absorb excess moisture, facilitate air-flow and prevent compaction of the compost; carbon is used by organisms for energy production. Browns are often referred to as the "dry" component of compost.

• Examples: brown leaves, sawdust, wood chips, paper, cardboard, newspaper, hair, nail clippings, drier lint

Compost bin with fresh materials
for the microbes and worms

To make a compost pile, it is best use a combination of materials that are shredded or chopped up. This makes it easier for microorganisms and worms to feed on the materials, which in turn breaks these materials down faster.

However, just because it was once living or came from a living being, does not mean it should go into a compost pile. Avoid raw and cooked meats, fats, oils, milk, cheese, manures, weeds with flowers/seeds, pesticide treated plants and grasses or you risk inviting creatures to dinner, a foul rotten smell, and killing off the good organism responsible for making compost.

All organic (living) matter is made up of a substantial amount of carbon and a small amount of nitrogen. To make compost, the system has to have the right balance of browns (carbon) and greens (nitrogen). Ideally, a 30:1 ratio of carbon to nitrogen results in a fertile, sweet smelling compost. For the home gardener, trying to figure out how to get to this ratio is more complicated that it needs to be.

Chance of frost

It is mid-May and well past the time for the last chance of frost for my area. But, this morning I woke up to hear the bad news on the radio: "frost advisory for tonight...temperatures in the low 30's". ARGH! Not the weather I want to hear, especially after just giving away all my extra plants. 

Nonetheless, there is a lesson to be learned here...

In the spring and fall, it pays to keep any eye on the nighttime temperature forecast. By monitoring temperatures at the beginning and end of the gardening season, you will have a chance to protect temperature sensitive plants and vegetables from frost.

Plants are classified according to the minimum temperature they can tolerate:

• Hardy - plants that can withstand a hard frost
• Examples: broccoli, cabbage, garlic, peas, radish, turnips 

• Semi-hardy - plants that can withstand a light frost
• Examples: beets, carrots, cauliflower, lettuce, parsley, potatoes

• Tender - plants that can be killed or injured by a light frost
• Examples: beans, corn, cucumbers, squash, tomatoes

• Very tender - plants that cannot tolerate cold weather or soil
• Examples: eggplant, peppers, watermelon

A light frost occurs at temperatures between 28-32oF. A hard frost occurs at temperatures below 28oF. 

Luckily the temperatures for tonight are not expected to dip below 32oF, so a "light frost" is probably the worst that can happen. 

Tomato plants all warm and cozy (hopefully)

I have taken a couple of measures to help prevent frost damage. This evening, I watered the soil thoroughly to help insulate the hardy and semi-hardy vegetables from frost. Wet soil holds heat better than dry soil, thereby protecting roots and warming air near the soil. 

For the tender vegetables, I covered the plants with a lightweight garden fabric. The idea is to create a tunnel to trap heat that is radiating from the ground. It is important to remember to remove the covers the next day to allow the sun to warm the soil and to prevent the temperatures under the "blanket" from getting too hot.

Luckily I haven't planted the very tender vegetables in the garden yet. I would have covered very tender plants with a double layer of a lightweight garden fabric (or a single layer of medium-weight fabric) or used plastic sheeting to create a mini-greenhouse.  

Alas, we are at the mercy of the mother nature. Whatever happens, happens.

Tonight I will also cover up to keep warm and cross my fingers and toes that the weatherman got the weather all wrong...again.