Garlic scapes, yellow spinach, and listen-while-you-work

 

Garlic scape harvest. Photo Wren Vile

The seasons are changing, and I notice fewer people are searching my website for Winter-kill temperatures and more are searching for garlic scapes, and (sadly) sprouting green potatoes!

We’ve been harvesting scapes from our hardneck garlic for over a week now and have been tackling the sequence of tasks that scapes act as a prompt for:

  1. Weed the hay-mulched broccoli and cabbage beds next to the garlic
  2. Weed the garlic
  3. Carefully lift out the hay-mulch-and-weeds combo from the garlic beds, into wheelbarrows
  4. Take it to the broccoli and cabbage beds and use it to top up the mulch there.

This gives the garlic good airflow and helps it dry down (our scapes arrive 3 weeks before we need to harvest). I notice it’s earlier this year. We may be harvesting at the end of May, rather than in the first week of June. We need to clean and prepare the barn where we hang the garlic to cure, and service the box fans we use to help that process (our climate is too humid to cure alliums without fans). For a lot more about garlic throughout the year, see the “alliums” category of posts.

What causes spinach leaves to turn yellow?

A bed of healthy green Reflect spinach on May 3
Photo Pam Dawling
A bed of sad yellow Reflect spinach only 10 ft away.
Photo Pam Dawling

On a less happy topic, we have been puzzling over the difference between one bed of spinach (green) and another about 10 ft away (yellow)

We had two beds of transplanted Reflect spinach from the same planting that came out very differently this spring. One developed yellow older leaves, the other stayed green. Seizing an opportunity, we transplanted the troubled one (30W) directly after tilling, on 3/2, without allowing the turned-under weeds to decompose. We did spread compost before tilling. Although initially healthy, later the older leaves developed all-over yellowing (not just between the veins). The other bed (27W), transplanted 3/18, about 10 feet away, has stayed healthy and green, up until May 14. We’ve lost track of when it was tilled relative to planting. Or, because we had such wet weather, we might have broadforked rather than tilled. Both beds now have pointy leaves and are getting ready to bolt. No difference in that. Our other beds of spring spinach, transplanted 3/5 and 3/13 are between the two mentioned in color. Is the problem entirely to do with the decomposing weeds (and the micro-organisms they are feeding) tying up the nitrogen? It looks like that.

In an effort to save the yellow spinach, 30W was weeded around 5/2 and the bed was sprayed in the evening 5/3 with seaweed extract. It rained 0.1″ the night of 5/4 and again 5/5, then no more rain before the second set of photos 5/9 – could the seaweed have washed off before it could be absorbed? We did not add a spreader/sticker (soap) to the seaweed spray. There might have been overhead irrigation, which could have washed it off. We don’t remember when it was irrigated relative to the seaweed spraying.

We also don’t know if there were differences in transplanting techniques between the beds, but as both beds were transplanted by several people working together, we can probably rule this out.

The bed of green spinach on May 9 – note how the leaves are pointy – the spinach is preparing to bolt.
Photo Pam Dawling
In 2016 both beds had spring spinach (three year rotation).

30W (yellow) then had buckwheat, compost and late squash 7/18/16, followed by winter wheat.

In 2017 it had compost, tomatoes 5/2 and winter wheat.

In 2018 it had buckwheat and soy, compost and late bush beans 8/3, leaving weeds over winter.

Total about 14 months food crops.

27W (green) had buckwheat and soy followed by oats in August 2016.

In 2017 it had compost, spring turnips, buckwheat and soy, compost and lettuce in August, followed by weeds over the winter.

In 2018 it had compost, carrots 3/27, compost, turnips 8/6 and weeds over the winter.

Total about 11 months of food crops.

The yellow spinach (no greener) on May 9.
Photo Pam Dawling
  • Possible causes of yellow spinach leaves include poor drainage, soil compaction, damaged roots/poor root growth, high soil pH, too much or too little water, too low or too high a temperature, or perhaps cold temperatures followed abruptly by very warm temperatures, 80°F or greater; nutrient deficiencies or disease. In our case, the beds are close together, receiving identical weather. Perhaps 30W is a bit drier.
  • Nutrient deficiencies may occur due to insufficient amount in the soil or because the nutrients are unavailable due to high soil pH, or nutrients may not be absorbed due to injured roots or poor root growth. Our roots grew OK, we don’t tend towards alkaline soil
  • The most common nutrient problem associated with chlorosis is lack of iron, but yellowing may also be caused by manganese, magnesium, boron, zinc, or nitrogen deficiencies.
  • Iron deficiency starts on young leaves and may later work towards the older leaves (which initially had enough iron, as a transplant). Can occur in water-logged soil. The veins can remain green. Not the problem we have – our older leaves are yellower.
  • Deficiencies in manganese, zinc or nitrogen develop on older leaves first and then progress upward.
  • Within older leaves, magnesium is transported from the leaf’s interstitial areas to the veins, resulting in yellowing of the areas between leaf veins. This creates a marbled appearance, a typical symptom of magnesium deficiency. Our leaves were yellow all over.
  • Nitrogen deficiency. Overall yellowing (including veins). The lower, older leaves appear yellow first as the plant moves the available nitrogen to the more important newer leaves. Spinach is sensitive to inadequate nitrogen. Our main suspect.
  • Boron deficiency also yellows the leaves and stunts spinach plants. We do tend to run short of boron, and my approach was to add boron before brassicas. We haven’t added any for several years and the only brassicas in these beds were turnips in 27W in spring 2017 and fall 2018. Did we add boron in 2016/2017?
  • Spinach is a heavy feeder. Feed with compost tea, manure tea, or fish emulsion when plants have four true leaves. Side dress with compost tea every 10 to 15 days. Mix 1 tablespoon of fish emulsion and 2 tablespoons of kelp extract per gallon of water; use about one cup per one-foot of row on a weekly basis until plants are about 4″ (10 cm) tall; then feed two more times before harvest. Add mature compost to planting beds twice each year.
  • Fusarium wilt or fusarium yellows (also called spinach yellows) is a fungal disease which infects plant vascular tissues. Fungal spores live in the soil and can be carried by cucumber beetles. We certainly have lots of striped cucumber beetles! But these plants did not wilt. See the photos here:
  • Harvest to Table is a great website with lots of reliable growing information.
  • Identifying nutrient deficiency in plants
  • Guide to Symptoms of Plant Nutrient Deficiencies
Listen While You Work

Harold Thornbro of The Small Town Homestead interviewed me about hoophouses and you can listen to the interview here. It’s about 50 minutes.

I also gave an interview for the Yale Climate Connections

This one is short (1 min 30 sec) and more about Twin Oaks Community than farming in particular.Play it directly above, or See the webpage here

There is also a link to a longer CNN story about Twin Oaks

2 thoughts on “Garlic scapes, yellow spinach, and listen-while-you-work”

  1. Hi.
    Sorry I can’t get your contact us form to work it keeps telling me to try again later. I originally arrived at this site on a much earlier (2017 or 2018) blog post. I just searched garlic and got this post.
    Here is the message I tried to send:
    I forgot if I needed to cut the “flower” or “scape” off. Now I see I’m supposed to. But they have already been around for several weeks.

    I plan to cut them today as soon as I get home… but I’m wondering if I’m too late. (I think some of the plants are starting to wilt….) How long should I give them to try to form more bulb? It’s been raining a lot so I only just now started to water with a sprinkler as well.
    So included in that… how long should I give them with water… then how long without? (so I’m not harvesting them too wet — though I need the ground somewhat wet in order to even dig it..)

    Now that I discovered your blog I’ll be reading too. 🙂 Just need a quick answer so was looking to contact *someone*. — oh yeah and I’m in Colorado. Kinda important. We got snow in May. I don’t even really look at my garden until after memorial day… (ducks).

    Thanks much!
    – Sharon

    1. Hi Sharon,

      Sorry about my contact form – I’m having trouble with it, and trying to fix it. Then I had internet problems too!
      About garlic scapes – I see you are in Colorado, so probably your garlic matures later than ours. If it’s very close to harvest time, you will not get bigger garlic by removing the scapes. How mature is it? Try cutting a few bulbs of the hardneck garlic across horizontally. If there are little airspaces around the central stem, then it is mature enough to harvest. If not, then I’d suggest going ahead with removing the scapes. The other test is to look at the leaves. Counting down from the top, you want about 5 green leaves to form good wrapper layers. If the sixth leaf down is brown at the tips, it’s probably ready to harvest – therefore too late to do any more growing. But if the leaves are more green than that, there is potential for growth (rather than drying down), and you could gain by removing the scapes. Thirdly, how close are you to your usual harvest date? Or are other local growers harvesting already?
      Next about watering. You are right that you don’t want tight baked soil when you dig up your garlic, as it will damage the bulb. And be very hard work! On the other hand, if they are not going to make any more growth, they don’t need water.
      That’s about all I can say on this, over the distance.
      All the best, Pam

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