How To Deal with Garlic Rust

rusty garlicDespite all my good preps, my garlic succumbed to rust. Aggghhhh!

I’ve been a proud garlic grower for 23 years. Kilo braids were my summer pocket money when the girls were babies. Christmas time at Moffat’s cottage was for sorting and cleaning garlic. Visitors were roped in and always left with a stash of beautiful bulbs.

Those were the days.

girls and garlic

3 years ago, I experienced rust for the first time. And I’ve been re-learning garlic ever since. Thanks to our friends Setha and Roddy from Setha’s Seeds, for sharing their knowledge and speeding us along the path. You can join their newsletter here.

Rust is a fast spreading fungus

Rust makes your plants look, well – rusty! The raised, orangey spots that cover the foliage are the spring spores. They cover the foliage quickly when conditions are ideal and in a severe case, the leaves yellow, shrivel and die. With the foliage unable to convert energy in its usual efficient style, bulbs are small, but still edible. And, by the way, all good for seed the year following.

Rust spreads really quickly through touching leaves, wind, being knocked about and rain. Wet foliage and mild temps create the perfect environment for spores to multiply, making spring a rust prone zone.

Where does rust come from?

Garlic rust lives in the foliage of alliums (maybe other plants too?). Spores blow in from as far away as your neighbours. The removal of infected host plants and crop debris is an important part of management because (god damn it) rust never sleeps.

rust on wheat

Technically garlic rust is it’s own particular allium related strain, but we’re wondering if it came via my crop of wheat this year. There was no other rust  in the garden, and my neighbours are acres away. The wheat got it bad, then sure as eggs the week following, the first bed of garlic (which happened to be right next door to the wheat) got it. A week later the second garlic bed, a bit further down the garden, went down. This blade of rusty wheat looks just like the rusty garlic don’t you reckon.

Prevention

Super infectious diseases like rust are difficult to manage organically, so its smart to put your best prevention foot forward.

Separate susceptible crops.

  • Plant alliums (chives, leeks, onions etc) as far from each other as you can. That whole wheat to garlic rust thing has really taken me by surprise and I’m wondering just how ‘separate’ the different strains of rust really are. Silverbeet, celery, grass, hollyhocks, oats, parsley, mint to name a few – are these guys potentially hosts too? If anyone out there knows more on this, we’d all love to hear.
  • If rust shows up in perennial alliums like chives, leeks or bunching onions you may want to get rid of them. Perennials keep the fungal spores alive and in your system. Tough call … I hear ya. Life without perennial leeks is unimaginable.
  • Though leeks (include elephant garlic and perennials here), may get the odd rusty spot, they carry on and wont go under. They are however still hosting it. Keep your eyes peeled I say.
  • At my place, shallots and onions, bop along with no rust problems at all.

Free draining and/or nourishing soil is key. Heavy clay (wet feet) and likewise poor sand (too dry) are the most susceptible. It’s no wonder – imagine how poor the mineral uptake is in either of these stressful situations.

Space well. Studies that show rust is minimised with good air movement, seem to be on the money. This year I increased my usual 10cm spacings to 20. Twice as much gap for weeds and half as much crop – grumble grumble. Spurred on by Roddy, Setha went bigger still – leaping out boldly into 30cm. Which is in line with my recent readings, at 30cm the incidence of rust is greatly reduced. And to date Setha is holding back the tide of rust and her garlic’s growing strong.

Or be wild. When Setha shared with me a story of seed garlic growing in a weedy wild fields and remaining rust free – it weirdly felt right. Bit less fuss, more resilient. This idea totally floats my boat and I’ll have a play with it next year.

ramial chips

Ramial Woodchips are the mulched up small twiggy bits from deciduous trees. There’s such alot of nutrient and energy in the part of tree that grows leaves, and using it for mulch stimulates amazing soil life. I’ve been playing about with them for the past few years and am falling in love here. Though they are new to me I’m including them in my strong soil plans. This kind of gardening I love because it’s full circle and doesn’t involve shopping.

Sound nutrition will always put you steps ahead of the game no matter what problem you are dealing with. Over doing nitrogen in your bed preps feeds rust like crazy, so keep things balanced and certainly don’t side dress with nitrogen based fert. on rusty crops. Though there are many passionate advocates for balanced soil being the magic cure all, it’s just one part of the equation. Don’t under estimate the part that environment plays in this disease.

nettle

Milk and Herb Teas. Milk is a wonderful fungal prevention spray. Dilute it 1:10. Fermented stinging nettle tea and also horsetail make for robust cells and strong leaf cuticle – just what the doctor ordered.

Plant early. March or April plantings give you the best shot, by ensuring bulbs are already a good size when rust hits in spring. Early garlic varieties will be our champion.

buckwheat

Crop Rotation. A 3 year gap before growing alliums on the same bed again is my goal. I’m wondering too, if I need to change my rotation about and swap out my pre garlic nitrogen fixing lupin for potassium drawing buckwheat. Mmmm, more pondering to do here.

EM and seaweed foliar sprays. Even though my crop was a complete disaster this year, I’m still backing my wonderful biological sprays of seaweed and EM. They keep my orchard in top nick and it’s now fungicide free. Things maybe taking longer to reach this place in the vegie patch, as annual gardening brings alot more pressure.

I sprayed EM allover the vegie patch after the rusty foliage removal. In my mind all those Effective Microorganisms gang up and make like Pac-men – gobbling up the bad guys and becoming the rulers.

What to do when rust hits

Don’t spend too long dilly dallying. If you want to try save your crop time is of the essence, especially if the weathers dismal.

Trimming off infected leaves helps if you get to it quickly enough. The key is to check daily and trim off the infected foliage as it appears. I’ve been doing this for the past few years, and managed to hold the spread back, but this year it was like wildfire. Introduced by the wheat (so say I) and fostered by 9 days of constant light drizzle that kept the foliage damp. Followed by a windy 2 days that spread spores far and yonder for a fungal take over.

Here’s what Setha would’ve done

Trim the worst affected leaves on a hot still day. Bag and remove. Spray Environmental Fertiliser vegetative foliar and reproductive foliar depending on stage of growth. Remember to switch back to the Vegetate foliar when the bulbs set. Foliar spray weekly or fortnightly. Trim leaves again if need be.

Housekeeping. Clean up bits of infected crop carefully. Spores will fling about with the movement – its unavoidable, just do your best to minimise this. Take a sack with you and put infected matter directly into it. Then burn it. You’re a brave person to compost it (although I’ve read some that do). Even with a well managed hot heap I’d still be loading it onto the bonfire.

Crop removal. Hardcore, but this was my solution this year. Thanks to the weather, the spread was super fast and I wasn’t happy with all those spores hanging out in my patch. Besides, I was feeling lazy – knowing I’d go to all that effort and end up with squitty bulbs. My garlic’s were too small when the rust hit, and they don’t grow prolifically with rust, especially when the foliage is gone. Perhaps if they were formed I may have got stuck in.

Fungicides are an option, if that’s the way you roll. Last year in desperation I used Kiwicare Organic Super Sulphur, as well as trimming off infected leaves and managed to hold it back and grow good sized bulbs. It was good to try it out, but my heart just isn’t in fungicides and my heart leads the way.

Garlic alternatives

  • Garlic chives provide a mild hit if tossed in at the end of cooking, though chives can host rust, so keep a look out.
  • Garlic can be harvested early, pre rust and minced up tops and all and frozen or dehydrated. It wont store ok, you need to process it.
  • Elephant garlic (being a leek and all) wont come down with rust like true garlic does, so this is an option as a roasted vege. The flavour is barely garlic but it looks just like one and your friends will be impressed at the size.

I’ll be tracking down a grower and buying some in for next years eating – supporting a local organic grower is an excellent alternative. I have a feeling they’ll be selling out fast this year!

perennial leeks

My garlic plan for 2019

  • I’m shifting all my perennial leeks down the back to hang out with the avocados and citrus. I know the spores can trek miles and its probably not far enough, but its further than they were. I can’t quite let them go, but they do at times get the odd spot of rust.
  • For the past few years I’ve been brainstorming with Matt about ways to keep the spring rain off the garlic while still ensuring good airflow. And after this years flop, I’m going to experiment with growing under cover through spring.
  • Early garlic is a definate
  • I’m also going to channel my inner wild girl and let some garlic grow as part of the orchard ground storey. I’ll solarise a beds worth this summer, spread a layer of compost, mulch it well and let it be. Matt’s going to believe it when he sees it if I can last without weeding it!
  • I’m considering growing a few containers worth in the berryhouse where there are no alliums and (touch wood) no signs of rust either. I wouldn’t usually consider containers as an option but I’ve noticed quite alot of rust free garlic in containers at consults (yes I’m secretly spying on all your crops while we talk). Perhaps the extra drainage is the key?
  • The vegie patch is going to have a rest from garlic for 2019. 2 whole beds for somethings else. Wohoo!

It’d be great to stay in touch with each other about what is and isn’t working, so we can find a way forward with this. Let’s suss out a way to manage rust in a simple, whole fashion.

 

 

 

 

 

 

 

Comments

  1. Thanks for sharing this information and your thoughts. It’s so frustrating aye. I took a break from garlic this year but will try again next year. I imagine you’re familiar with Charles Dowding’s YouTube channel. He put up a garlic video recently and also mentions rust as increasingly difficult to manage. From memory he said he has much better results growing under cover.

    • Yes Kirsty – I’m looking forward to cracking garlic under cover. It’ll be tricky to provide airflow as well but through trial and error we’ll find a way. I’d pop it in my greenhouse a la Charles 🙂 but it’s way too hot for the final months of finishing for it. 6 months to ponder and hatch a plan! Thanks for writing in
      best Kath

  2. Claire Lynch says:

    Hi Kath. Last year my garlic got the dreaded rust which decimated my wee crop, so this year, i decided to plant it in a large container away from where I planted it last year…and same story..the rust has just started. So after searching the internet, I read about Condys Crystals….i.e. Potassium Permangate. An old fashioned remedy and tonic and is supposed to help rust and curly leaf.. So today, I sprayed my garlic and peacherine..rate is 1/4 tsp per litre of water. Then you drench the soil around the plants to kill any spores in the ground. Fingers crossed. Will let you know if it works. Makes me wonder what toxic sprays commercial garlic growers use to,prevent the rust as its a worldwide problem it seems. Kind regards, Claire . Palmerston North

    • Yes, its a tricky beast alright. The vicious cycle we find ourselves in here is that when we kill of the bad fungi we also kill the good, leaving our crops more and more vulnerable requiring more and more fungicide. Yes I’ve read Wallys article about Condys crystals (kill mode here too I’m afraid) and would love to know how you go with it. For me I’m looking to outwit it without the killing mentality, rather a building one. But it’s all theory at the mo and we are all learning here together. I appreciate you taking the time. Stay in touch with how you get on.
      kind regards
      Kath

  3. I think you’re on to something with the rain cover.
    First year I planted garlic it was under a tunnel of frost cloth to protect the plants from the westerly winds. It still allows some water through for the plants and liquid fertiliser teas.
    I got rust much later then everyone else and only after the covers had been removed.

  4. Thanks for confirming and helping us to keep positive. First garlic season in lower North Island NZ after growing great enormous, wonderful garlic in Victoria, Australia. We did EVERYTHING on your suggested list, as we’d heard garlic rust was rampant in NZ and so had researched. This week, vicious wind, followed by drizzle, grey, damp and more wind. The entire 400 plants are covered in rust, since Wednesday this week. Today Friday.

    The cover was taken off a few weeks ago 🙁

    We’re going hardcore, as you did. Harvest the lot, process by dehydrating, freezing and maybe some in Verdurette (basically anything green 4 parts to 1 part good salt.

    And we’re moving to the Hawke’s Bay (a little bit unexpectedly) in two weeks, so the silver lining is we won’t have to come back to harvest the garlic at the end of December. And hopefully will leave the garden clean of as many spores as possible for the next people to take over and use the beautifully prepared and nutrient dense soil! (Hard leaving a garden!)

    Thank you, helps with the pain of loss!!

  5. Aimee Congreve says:

    Be careful planting in the berry patch. We have raspberry plants that have got rust the last two years at exactly the same time as the garlic.
    Some Oxalis species can harbour the spores overwinter too.

    • A timely comment Aimee – I have rust in the berryhouse, not on my raspberries but in my herbal border on the marshmallow – it’s really going off at my place at the mo, so yes no garlic in the berry house!

Speak Your Mind

*