Fertilizer schedule for container hops

[brewmasterthis]

Long time reader and first time post

I have 5 year old Cascade growing in a very large self irrigating planter (SIP). I built the SIP from a extra large plastic storage container and it should hold the root ball for a few more years. I've gone the chemical fertilizer route (I know some folks call this the devil's brew) but SIPs require well draining container mix (not soil) so it's mandatory not to add any material that clogs up. Besides, I got over 8 lbs yield last year so I think it does very well.

Can anyone recommend or provide hard numbers for a chemical fertilizer schedule? I calculated my fertilizer need and would appreciate a peer review.

Research turns up two references about fertilizer requirements for hops, a 1994 article published by OSU Extension and a more recent one from UVM Extension. They mostly agree on NPK requirements for high yielding hops, namely: 100-150 lbs/acre of N, 20 lbs/acre of P and 40-60 lbs/acre of K. Since I live in the Northeast, I used UVM's figures.

Excerpt from UVM Fertility Guidelines for Hops in the Northeast:

A hop crop will require a substantial amount of nitrogen (N) to meet growth requirements. A high yielding hopyard can remove between 100 to 150 lbs of N per acre from the soil. Nitrogen application rates are often based on knowing your whole plant biomass yield. Higher yielding plants will obviously require more N per acre to promote plant growth and development. A whole plant biomass yield of 1000 lbs/acre will remove 80 to 90 lbs of N per acre from the soil. As the cone yield increases to 2000 lbs/acre the hop plant can remove 150 to 170 lbs/acre of N from the soil. Nitrogen rates should be based on yield but also soil organic matter level and/or soil type.

Cascade yields upwards of 2000 lbs/acre of cones and I assume that removes 150 lbs of N/acre per year. Based on this, I calculate my Cascade's Nitrogen requirement (C) to be:

C = (8 lbs cones) x (150 lbs N/acre)/(2000 lbs/acre) = 0.6 lbs Nitrogen

I use All Purpose water soluble Miracle Grow which has 24-8-16 (24% Nitrogen, 8% Phosphorus, 16% Potassium) because this ratio aligns well with the recommended needs published by OSU and UVM. From this I can calculate how much fertilizer (F) I need to use per growing season.

F = C x (lbs Fertilizer/lbs Nitrogen) = 0.6 x (100/24) = 2.5 lbs Fertilizer

This seems high to me so I'm going to stick with fertilizing with every watering until flowering for the remainder of this season.

My best guess at a fertilizing schedule is:
Plain water until June 1
Fertilize after June 1 until flowering
Add Potassium? once cones start developing (Potassium Sulfate 0-0-45)

Cheers,
Brewmasterthis

 

[hardrain]

So I'm not really sure what the question is

The math looks good to me except potentially your scale-down. Most pro growers in the NW are looking at (and of course this is dependent on a lot of variables) 1,000 plants per an acre, and 2lb dry/plant.

Your phrasing could mean different things. You either have an undisclosed number of hop plants that are five years in age, yielding 8lb per plant (of which I have to assume wet weight, and what follows assumes that your average, not your peak). OR five one-year aged plants, presumably yielding 8lb total (I'd assume dry weight).

The scale of wet:dry is typically 5:1. So interestingly either way it sounds like you're yielding 1.6 lb dry/plant. Therefore I'd consider dividing by 1,600 instead of 2,000 in your formula to take into account some kind of inefficiency in your setup (which could be root space, height, day length, ect...all leading to less plant material), and therefore less nutrient extraction.

I should also say it's unclear to me from these recommendations, which I've seen in a variety of places, if they're assuming the plant material besides the cones is being returned to the field or not. As so much of the nutrients are tied up there, that's going to make a big difference. I'm going to speculate that they assume the entire plant is removed, which sounds like how your setup is working as well.

FWIW I'm very much against this type of growing, but see little harm in it at your scale...and also they're of course your hops . Those numbers line up with what I've seen elsewhere but part of the problem with this type of growing is micro-nutrients (esp boron and zinc, but the current science on the very wide range of this issue is incredibly lacking in completeness right now) and ph (shoot for 6.5), both are heavy influencers on hops, so check on those.

These are probably bigger problems at a bigger scale when it could lead to pest pressures and disease issues you likely are more easily able to monitor, so not a huge deal. However, there are also a very wide variety of different compounds in hop cones, the dynamics of which are really just starting to be explored, I could see (theory, no data in hand to back this up) over-simplifying the nutrient additions via these methods having a negative impact on the diversity of the aroma compounds in your hops. You could potentially check in on this by sending the cones off to be tested for fun, but remember event he testing right now is limited, especially on the aroma side.

Hope this helps!

 

[Voodoo]

If you're only running one plant in an SIP (basically lazy hydroponics), why not just go out and get liquid ferts from any grow shop or garden center and toss them in the water you're watering with?

I do this all the time in my SIPs with Botanicare's Soil Grow / Bloom lines depending on what the plant needs. Generally, whatever these companies recommend on the back of the bottle, try it at half strength first and then push harder from there.

 

[brewmasterthis]

Don't want to start a chemical vs natural fertilizer argument. I left out details to keep my post short so here is more background to answer questions about my setup.

Five or more years ago, I planted Liberty, Nugget and Cascade in my backyard right on the edge of the woods far from my house. My choice was far away or right next to the house due to sun exposure and what the wife would tolerate. Since a friend told me that his hop roots got out of control and took over his deck I chose to keep them away from the house. As it turns out, I suck at gardening because my choice led me to neglect my hops. In a nutshell, my modest hopyard was out of sight and therefore out of mind. Lack of consistent watering, fertilizing, and a very competitive ecosystem (ie. pests and diseases) from the nearby woods resulted in poor to neglible yield.

Two years ago, it was time to either give up or give them one last chance. This SIP setup caught my eye since I decided to move my hops right next to the house. This change provided many advantages: 10 hours/day direct sun; Second story anchor points; Right next to hose spigot, Provide natural shade; Root system containment; Easy daily inspection. That Fall, I dug up my Cascade which was the hardiest of the three and put into the largest SIP I could make and stored it in my garage over the winter. In Spring of last year, I wheeled the SIP out and positioned it under a large picture window and ran 2 strings from the 2nd floor eaves and down to a cleat so I could raise and lower them from ground level. I trained 3 bines per string.

The difference was night and day: over 8 pounds of wet cones which resulted in 34 ounces of dry hops. I attribute this to daily attention since I would scout for problems from inside while drinking my coffee and made sure the water reservoir was replenished. The bines reached the top of the strings and I kept feeding more length to the point of looping the bines over an intermediate plant hook. Final length was 22 feet. As far as I know, this is in line with the upper yield one can expect from a single Cascade plant, no matter what method is used.

Anyhoo, back to the topic...

The scale of wet:dry is typically 5:1. So interestingly either way it sounds like you're yielding 1.6 lb dry/plant. Therefore I'd consider dividing by 1,600 instead of 2,000 in your formula to take into account some kind of inefficiency in your setup (which could be root space, height, day length, ect...all leading to less plant material), and therefore less nutrient extraction.

My yield is over 2 lb dry/plant so I think 2000 lbs/acre is correct

I should also say it's unclear to me from these recommendations, which I've seen in a variety of places, if they're assuming the plant material besides the cones is being returned to the field or not. As so much of the nutrients are tied up there, that's going to make a big difference. I'm going to speculate that they assume the entire plant is removed, which sounds like how your setup is working as well.

I don't cut the bines during harvest in order return nutrients back to the roots. After a month or more I cut the bines down when they start to look unsightly.

In response to why not just use liquid fertilizer, that is what I'm doing. Yes, this is lazy hydroponics which suits me fine! For water soluble All Purpose Plant Food Miracle-Gro, the instructions say to mix 1 tablespoon per 1 gallon water for outdoor plants which I assumes creates a solution of 24-8-16 fertilizer.

Those numbers line up with what I've seen elsewhere but part of the problem with this type of growing is micro-nutrients (esp boron and zinc, but the current science on the very wide range of this issue is incredibly lacking in completeness right now) and ph (shoot for 6.5), both are heavy influencers on hops, so check on those.

My pH measures 6.5 so I'm good there. Miracle-Gro also has Boron, Zinc plus more, see below.

From the Miracle-Gro label:

Directions For Use
Outdoor Plants: Mix 1.5 tablespoons per 1.5 gallons of water in a water can. For best results, soak the soil at the base of plants every 7-14 days.

Miracle-Gro Water Soluble All Purpose Plant Food 24-8-16
--- Guaranteed Analysis --- F 1198
Total Nitrogen (N) 24%

• 3.5% Ammoniacal Nitrogen
• 20.5% Urea Nitrogen

Available Phosphate (P2O5) 8%
Soluble Potash (K2O) 16%
Boron (B) 0.02%
Copper (Cu) 0.07%

• 0.07% Water Soluble Copper (Cu)

Iron (Fe) 0.15%
0.15% Chelated Iron (Fe)
Manganese (Mg) 0.05%

• 0.05% Chelated Manganese

Molybdenum (Mo) 0.0005%
Zinc (Zn) 0.06%

• 0.06% Water Soluble Zinc (Zn)

Derived from Ammonium Sulfate, Potassium Phosphate, Potassium Chloride, Urea, Urea Phosphate, Iron EDTA, Manganese EDTA, Sodium Molybdate and Zinc Sulfate. Information regarding contents and levels of metals in this product is available on the Internet at www.regulatory-info-sc.com

My goal is to improve and hence my seeking a recommended fertilizer regimen. This season, I moved to a better location (another advantage of container growing), added a secondary support system which creates room underneath to walk under and tracking growth and fertilizer amounts.

I do this all the time in my SIPs with Botanicare's Soil Grow / Bloom lines depending on what the plant needs. Generally, whatever these companies recommend on the back of the bottle, try it at half strength first and then push harder from there.

Voodoo, what fertilizer regimen do you use on your SIPs? Are you happy with your SIP system? I would love to know more about it, the containers, substrate, yield, etc

If anyone is interested, I will post pictures of my setup.

Cheers!
Brewmasterthis

 

[hardrain]

Don't want to start a chemical vs natural fertilizer argument.

Yep me neither, just pointing out some things to make sure you're rounded out. Happy you're doing your thing.

over 8 pounds of wet cones which resulted in 34 ounces of dry hops.

One final thing since you seem science inclined -- I'd focus a little more on this section, since something is off (totally fine for home use, but if you're interested in optimizing). You're either harvesting too late (you want to shoot for 77-80% moisture percentage at harvest) or under-drying (shoot for 8-9%). That's where the 5:1 comes from, sounds like you're at 3.5:1 -- give this a shot come harvest time: https://www.uvm.edu/extension/agriculture/engineering/

 

[brewmasterthis]

Yep me neither, just pointing out some things to make sure you're rounded out.

Appreciate your advice even though we have different paths!

You're either harvesting too late (you want to shoot for 77-80% moisture percentage at harvest) or under-drying (shoot for 8-9%). That's where the 5:1 comes from, sounds like you're at 3.5:1 -- give this a shot come harvest time: https://www.uvm.edu/extension/agriculture/engineering/

Good idea. I could improve this process since this is unexplored territory. I didn't document last year but I recall my wet to dry ratio was more like 4:1. Used a primitive process involving window screens and my very hot attic and called it a day after 48 hours. Definitely will be more analytic this time around.

 

[Voodoo]

In response to why not just use liquid fertilizer, that is what I'm doing. Yes, this is lazy hydroponics which suits me fine! For water soluble All Purpose Plant Food Miracle-Gro, the instructions say to mix 1 tablespoon per 1 gallon water for outdoor plants which I assumes creates a solution of 24-8-16 fertilizer.


My pH measures 6.5 so I'm good there. Miracle-Gro also has Boron, Zinc plus more, see below.

My goal is to improve and hence my seeking a recommended fertilizer regimen. This season, I moved to a better location (another advantage of container growing), added a secondary support system which creates room underneath to walk under and tracking growth and fertilizer amounts.


Voodoo, what fertilizer regimen do you use on your SIPs? Are you happy with your SIP system? I would love to know more about it, the containers, substrate, yield, etc

If anyone is interested, I will post pictures of my setup.

I love my SIPs (24x24 tree planter boxes). This is the first year Ive gone full bore SIP for all my gardens and they are so much better than top watered containers in the hot, dry climate of San Diego.

Soil mix is Fox Farm Happy Frog / Fox Farm Ocean Forest, Worm Castings, Rock Dust, Steer Manure and Chicken Manure. I don't have a regiment that I stick to, I just gauge the plants by the way they look in the leaves. Usually this means I am giving them a light boost of bloom nutrients around mid july and I am foliar feeding the plants with epsom salt or CalMag once or twice a season depending on how hungry they get.

 

[brewmasterthis]

I love my SIPs (24x24 tree planter boxes). This is the first year Ive gone full bore SIP for all my gardens and they are so much better than top watered containers in the hot, dry climate of San Diego.

Voodoo, just checked out your hop garden. You've got a lot going on! Best of luck now that you cut the bull shoots and started over. My Cascade is at 19 feet with crazy side arm growth. Like you, I'm loving the ease and yield of SIP hops. The redwood boxes are a classy touch. Cheers!

 

[Voodoo]

Thanks for the love!

Admittedly, this is my first year running hops in SIPs, but my vegetables are all in SIPs and they're the reason I switched the hops over. The reduction in water consumption and continual hydration were my big motivators.

My veggies are in much smaller SIP containers (5gal global buckets) and see somewhat regular fertilization with liquid nutrients or foliar feeding and I haven't had any issues whatsoever.

 

[cram]

Here are some Centennial plants in 24x24 top-watered boxes in San Diego County. Input schedule has been a hefty top dress of composted chicken litter from the coop, and a recent switch to a 5-7-3 organic tomato fertilizer that was on hand after burrs started to form. Nothing fancy. But the plants are doing well this year. I'm curious about the SIP and reduced water consumption. Curious how much you're watering, Voodoo. I figure SIP is like an Earthbox but I need to research. View attachment ImageUploadedByHome Brew1466815678.119458.jpgView attachment ImageUploadedByHome Brew1466815692.845207.jpg

 

[brewmasterthis]

You're either harvesting too late (you want to shoot for 77-80% moisture percentage at harvest) or under-drying (shoot for 8-9%). That's where the 5:1 comes from, sounds like you're at 3.5:1

I didn't document last year but I recall my wet to dry ratio was more like 4:1. Used a primitive process involving window screens and my very hot attic and called it a day after 48 hours.

So... went to UVM Extension and found this Harvest Moisture Determination reference

Therefore if you place one hundred pounds of hop cones into the oast at 77 percent moisture (23 percent dry matter), it would weigh 25 pounds after drying down to 8% moisture [(100 lbs - (0.75 x 100 lbs)] = 25 lbs.

hardrain, unless I'm mistaken, 4:1 is the optimal wet to dry ratio

 

[hardrain]

So... went to UVM Extension and found this Harvest Moisture Determination reference

hardrain, unless I'm mistaken, 4:1 is the optimal wet to dry ratio

Ha, interesting. So actually "ideal" depends on those starting variables. Go to that calculator and type in 100 grams above the pretty colored chart at the bottom. If your 'ideal' dry matter is 23% (as in the example you quote), then yes. If it's 20% (the doc you quote says 20-21% is ideal for certain varieties including fuggles, tett, will.) you get a 21.7 lb dry / 100 lb wet calculation.

Picking ideal dry matter, from what I've read, isn't an exact science. You can optimize for alpha acids, or flavor profiles. There's some studies that say for flavor profiles you might want to go way lower than 20-21% dry matter.

In practice, for me, with several varieties, logistically having to plan in advance and pick them all at once, I've seen an average of just under 5:1 (not sure, call it 4.8:1). I also lose a bit of matter (oils, cone stems and leafs) during drying and handling, which I'm not sure are being captured in these calculators. So maybe my theoretical drying is more like ~4.5 or something. These extension studies, especially the newer east coast ones, are highly academic, which is great, but also a classic extension/farmer point of tension .

Anyway fun to explore, certainly. I've always just stuck with the 5:1 ratio as a rule of thumb. In practice with more than a couple of hops and many varieties, both the dry matter at harvest and time to quit drying are rounder numbers given all the different variables. I only brought it up because my rounded calc of your situation was more like 3.5 (8 lb - 34 oz), which is actually more like 3.77, and if you're closer to 4 without a lot of handling then that sounds more than fine

 

[Voodoo]

Here are some Centennial plants in 24x24 top-watered boxes in San Diego County. Input schedule has been a hefty top dress of composted chicken litter from the coop, and a recent switch to a 5-7-3 organic tomato fertilizer that was on hand after burrs started to form. Nothing fancy. But the plants are doing well this year. I'm curious about the SIP and reduced water consumption. Curious how much you're watering, Voodoo. I figure SIP is like an Earthbox but I need to research. View attachment 359726View attachment 359727

Well I never actually measured the volume of water that each planter box holds, but I'd guess it was 3-4 gallons at the bottom. My second year plants (which look remarkably similar to yours) need to be refilled every 2-3 days, my first year plants are more like once a week.

I also pour about 1-2 gallons of water on the top of the soil of the pots. You generally don't need to do this with established plants, but for the first year plants its a good idea to ensure that the soil at the top of the pots is good and moist.

The real beauty of the sub irrigation is that you never fully dry up on hot days. This was a continual problem in my 10 gallon top watered pots though the flowering season. The plants go through the water in the planter, and then begin to wick up water from the bottom as the soil dries out.

Another benefit is the hose fits neatly inside the PVC down tube, so watering is as easy as dropping the hose in and waiting for run off. This keeps the lower foliage dry and minimizes potential for mold on the lower growth.

 

[brewmasterthis]

Anyway fun to explore, certainly. I've always just stuck with the 5:1 ratio as a rule of thumb.

Agreed, this is fun. I use up my hops fairly quickly and store them in the freezer under vacuum in foodsaver bags so not overly worried. My hot attic gets a respectable 4:1 ratio. I remember my wet yield was over 8 lbs but didn't measure how much over. I did weigh my neighbors Cascade before and after drying in my hot attic and got a 4:1 ratio. After one season, not much data to go on but now I know I should shoot for 4:1 or more.

 

[brewmasterthis]

Well I never actually measured the volume of water that each planter box holds, but I'd guess it was 3-4 gallons at the bottom. My second year plants (which look remarkably similar to yours) need to be refilled every 2-3 days, my first year plants are more like once a week.

I also pour about 1-2 gallons of water on the top of the soil of the pots. You generally don't need to do this with established plants, but for the first year plants its a good idea to ensure that the soil at the top of the pots is good and moist.

The real beauty of the sub irrigation is that you never fully dry up on hot days. This was a continual problem in my 10 gallon top watered pots though the flowering season. The plants go through the water in the planter, and then begin to wick up water from the bottom as the soil dries out.

Another benefit is the hose fits neatly inside the PVC down tube, so watering is as easy as dropping the hose in and waiting for run off. This keeps the lower foliage dry and minimizes potential for mold on the lower growth.

Adding to this, my plastic SIP holds 4 gallons of water and recently going through 3 gallons of water a day (it's been hot in the Northeast). The SIP makes it easy to ensure your soil never dries out and minimizes mold issues. I will likely add a few more feet of string next week and switch to 0-0-45 if flowering begins.

 

[cram]

I appreciate the information, Brewmasterthis and Voodoo. I may have to look into the SIP for next year. Watering once or twice per week sounds nice! It's also clear from reading these posts that I can be more targeted in my input schedule. Happy growing!