Asparagus might seem like a plant not destined for the hydroponic system.
But asparagus loves moist soil that drains well and requires a rich, nutrient-dense growing medium, as well as no competition from weeds. This means it is a great hydroponic candidate.
Also, they will tolerate some shade if you are planning on setting up your hydroponic unit outdoors, but exposure to full sun will guarantee a better crop.
The main benefits of eating asparagus are that they are a great source of fiber, folate, and vitamins A, C, and K. Health benefits include weight loss, better digestion, and lower blood pressure.
Now that we know why you should grow asparagus hydroponically, let’s take a look at how to grow asparagus hydroponically.
- Benefits of Growing Asparagus in Hydroponics
- Growing Conditions for Hydroponic Asparagus
- Best Hydroponic Systems For Asparagus
- Starting Your Asparagus Hydroponic Crop
- How to Set Up an Asparagus Hydroponic Unit
- Maintaining Your Hydroponic Asparagus
- What We’ve Learned About Growing Asparagus In a Hydroponic System?
Also Read: How To Grow Hydroponic Kale
Benefits of Growing Asparagus in Hydroponics
Asparagus is a temperate zone plant, which means it requires warmth to grow and develop nicely. With hydroponics, you can adjust all the environmental conditions one tweak at a time.
By controlling the environment, asparagus can avoid going into dormancy as it does when temperatures drop.
Other benefits of growing asparagus are:
- More frequent crop rotation
- Water conservation
- You can adjust the climate
- You’re able to pump the plant with loads of nitrogen
Asparagus is a heavy feeder, which is perfect for hydroponics, as you can really give the plant as much nutrients as it can handle.
And a plant that is able to tap into an abundance of nutrients will become a healthier and larger producing crop.
Now, let’s focus on the optimum growing conditions for your asparagus to enjoy when in its hydroponic setup.
Growing Conditions for Hydroponic Asparagus
Asparagus is a monoecious plant, which means they can be separate genders, either male or female. The females will develop into a fern-like plant and deliver berries. Do not eat these berries. They are toxic to humans.
Male plants develop the stalk we’re all accustomed to eating. As a rule of thumb, you will need 25 plants to feed a family of four.
Asparagus was once thought to be closely related to the lily family, and then botanists decided it was related to Alliums, which are the species onions and garlic are a part of.
But upon closer genetic inspection, they decided it was its own family called Asparagaceae. The original home of asparagus is up for debate, but most accept Europe and western Asia.
Another oddity about asparagus is that it pops up in maritime habitats, which means it thrives in soil that is too saline for the usual weeds.
As a perennial crop, you will be encouraged to maintain the optimum conditions to ensure it lives a full and healthy life.
So, what temperature does this warmth-loving plant need?
As we’ve mentioned asparagus loves a warm environment. Your crop will be at its optimum growing potential when kept around 75°F to 86°F.
When the ideal temperature is reached and maintained, the crown of the plant will shoot upwards.
You will want to trellis and stake your plants to prevent them from toppling over.
If you are trying to germinate seed you will want to lower the temperatures to around 72°F - 78°F.
Temperature matters with asparagus as it will not absorb nutrients if it is too cold and will revert to dormancy.
As mentioned, asparagus loves nitrogen. Always ensure your plant has constant access to a well-balanced nutrient solution.
And an asparagus plant’s roots are very fleshy and can store loads of nutrients. A crop of roughly an acre can store 150 lbs of nitrogen, 37 lbs of phosphorus, and 170 lbs of potassium.
So, there’s no need to worry about overdosing the crop.
Check out our recommendations for the top nutrients solutions: Best Hydroponic Nutrients
Aim to keep the pH level of the solution around 6.0 - 6.8 and Electrical Conductivity (EC) around 2.4 - 3.0.
Asparagus loves getting as much light as possible. While they can tolerate some shade, you want the most out of your plants.
So in your garden or outdoor conditions, you will want to place them in an area that gets full sun.
If you’re growing indoors you will want to program the lighting schedule for 12 hours of day, followed by 12 hours of rest.
You can use a generic LED lighting rig like the MARS Hydro LED Grow Light, which will provide nice coverage with its reflective shield.
For more options check out our guide: Best Hydroponic Grow Lights
As the asparagus crown starts to shoot up you want to lift the light up.
The MARS Hydro LED Grow Light has handy adjustable tethers for moving the light to the optimum height.
Now, what system should you grow your asparagus in?
Best Hydroponic Systems For Asparagus
With asparagus’s long life span of up to 20 years, you will want to invest in a hydroponic unit that will last. A number of setups will work, these include:
- Deep Water Culture (DWC)
- Nutrient Film Technique (NFT)
- And Ebb and Flow
We’d suggest selecting a DWC as it will allow for the roots of the plant to really tap into the nutrients in the solution.
While you can upscale your crop potential with an NFT or Ebb and Flow system, it can be tricky to scale up production, so try with a smaller system first to iron out complications.
Asparagus DWC System
Our recommendation is to start the first year with a five-gallon bucket system like the PowerGrow DWC Hydroponic Bucket System.
Included in this package are the following:
- Five-gallon bucket with a net pot integrated into the lid
- Air pump
- Air tubing
- Air Stone
- Growing Medium
- And Rockwool seed starting packs
The above list is your basic requirements for a DWC hydroponic setup.
Setting up this system is pretty simple and can vary a bit depending on whether you’re growing outside or inside.
Asparagus Ebb and Flow System
If you feel like you’ve slam-dunked growing hydroponic asparagus, you can upgrade to an Ebb and Flow system, like the Active Aqua Ebb and Flow Grow System.
This is an advanced system that is expandable and can connect up to 48 pots. It has an adjustable float ladder and emergency shut-off valve, along with an LED emergency indicator light.
The pots themselves have two layers, an outer and inner shell, which makes investigating your plants’ roots easy.
All the tubing and fittings are ¾” and they come with a powerful 120v pump and timer.
Now let’s focus on how to start your asparagus crop.
Starting Your Asparagus Hydroponic Crop
With asparagus, you have two options for starting your crop, either via planting crowns directly or seeds.
If you source asparagus crowns you can get a headstart on your production. But be warned as these will be grown in soil, and can pick up and spread diseases to your system.
But generally speaking, a crown is just roots that are ready to be planted.
Growing from seed in the correct warm conditions will mean you have to wait at least three years before properly harvesting.
This being said, new modern hybrid plants (not genetically modified, these are bred), can now produce a spear that’s edible within 10 to 12 months, with full production achieved in 18 months.
When harvesting your asparagus you need to ensure you do it properly. These plants will be around for years, and sometimes you’ll need to let them flower. It’s recommended you allow them to flower every third rotation to maintain healthy asparagus plants.
To germinate asparagus seeds you need to allow for 10 to 14 days with a temperature around 72°F to 78°F. Using Rockwool will give you an easier transplant into the system you select and we’d suggest using Grodan.
Learn more about germinating seeds for hydroponics
Asparagus seeds are hardy and can take a knock of lower temperatures, but this will slow progress.
Make sure to select newly produced seeds, as older generations will be more difficult. And could result in a female plant.
You can keep the lighting schedule to 12 hours on and off. If you are wanting to harvest seeds you will need to take the risk and plant both sexes.
For those willing to take this route be sure to separate the edible harvest crop and seed crop.
How to Set Up an Asparagus Hydroponic Unit
As we mentioned asparagus needs as much light as it can get. You need to find an area that gets full sun for at least 10 hours a day if you’re growing outdoors.
If you are growing indoors, as mentioned, set the light schedule for 12 hours on and 12 hours off.
The actual area space is important to remember. If you have ample room, you should consider installing an amazing ebb and flow system, while those in a small indoor area will have to stick with a DWC.
Always ensure there’s enough ventilation in the indoor grow rooms to avoid mold and disease.
Many manufacturers will claim silent pumps, but we’ve yet to come across one that we’d be happy to hear 24/7. So, make sure your grow systems are out of earshot.
And asparagus needs room to grow in the solution so make sure to space them apart by at least an inch or two.
Once you’re happy with the location, follow the instructions in the system you’ve selected.
We’d love to assist, but processes can vary widely. The rule of thumb is to ensure that the pH, nutrient, and EC levels are correct.
Maintaining Your Hydroponic Asparagus
With asparagus needing such high levels of nutrients, you will be required to flush the system to avoid your plants getting too much dirt covering their roots. When the roots are coated in a very thick layer of nutrients they kill off the plant.
Also, high nutrient levels leave them vulnerable to root rot. Once again, flushing the system every 7 to 10 days will help avoid this issue.
Monitoring your plants' health for all fungal issues, stunted growth, and more is always in your best interest. And check your pH.
How you harvest your asparagus also affects their general health.
Learn more about Maintaining Your Hydroponic System.
At the first harvest make sure that there are a few spears from each plant before cutting. And always leave a few to flower.
The first harvest can take place within a year or can take three depending on the seeds or crowns you’ve sourced.
Allowing for some of the fronds to unfold and develop as this will conserve energy and health.
Make sure to only harvest for around 2 weeks during the first growing cycle. The next cycle you can extend the harvest to 3 weeks.
Spears should be cut when they are between 5 to 7 inches long. Any smaller and you’re stopping it from reaching its full potential.
What We’ve Learned About Growing Asparagus In a Hydroponic System?
Asparagus is an exciting crop, with many unique features. It is perennial, can adapt to conditions (cold or salty), and is monoecious.
But if you get the conditions for growing just right you’ll have asparagus for decades. And honestly, a great cutting to share with friends.
We’d recommend starting small with a DWC and then switching to an ebb and flow system which will be a tricky grow, but worth it.
If you need more information about growing hydroponic asparagus, please feel free to leave your questions below and we’ll try our best to answer them thoroughly.
And if you’re looking for a unique challenge, start with asparagus.