The hardest vegetables to grow can sometimes be the humblest to cook. Carrots to sweetcorn, we can all struggle with these seemingly easy crops.
These are the hardest vegetables to grow in the UK or similar climate zones. Where you have the wrong soil, not enough shade or daylight hours, or periods of frost, or even drought. Then these sensitive crops will fail.
There is hope though and we have surveyed more than 20,000 online gardeners and allotment holders to try and find their worst crop fails, and how they overcame the problems!
8 Hardest Vegetables To Grow
These came out on top of our survey and I have first hand experience of how time consuming and disappointing some of them are, most noteworthy is sweetcorn!
The hardest to grow vegetables require sunlight, soil or nutrient and watering schedules that make them high maintenance in the wrong setting. Hard to predict weather patterns such as frosts in May and floods in July can make sensitive plants prone to diseases and pests, or get root rot and die.
With a little bit of experience you can find the right setting and care for them though! So let’s all learn from mine and many other mistakes before me.
Artichoke Are Hard To Grow For Beginners
Artichoke are native to the Mediterranean and so thrive in those conditions with a pretty stable temperature and rainfall through the growing season. In the UK and colder or hotter climates care must be taken to ensure no drought periods and not too much sunshine.
It is also the initial germination that can be hard to achieve. You need two weeks of vernalization where you introduce the seeds to cold temperatures, below 10C. This can be a complete failure and you will get poor germination rates of your artichokes.
Asparagus – Not The Hardest For Experienced Gardener’s
Asparagus is one of the hardest vegetables to grow as it takes so long to see a harvest – three years from planting crowns. Not just that, there is a lot that can go wrong in those three years. Here is our list of ways to prevent failure, but still be prepared for one or more of these issues in the three years to harvest!
- Where you have planted your asparagus must be kept weed free – do not go full on with a hoe though. You will damage the tender roots of the young asparagus plant. A good layer of mulch over Winter really helps as a weed suppressant.
- Feed your asparagus bed through the three years! A general purpose feed is good but bone meal is ideal.
- Plant asparagus crowns which are one year old plants and do not plant by seed. This shortens your harvesting window to three years and not longer.
- Weed out female asparagus plants is a good idea depending on the cultivar as you will not need them or any seedlings produced.
- In Summer the foliage will grow tall and be prone to movement in the wind, causing disruption to the base. To avoid this issue you must stake it.
- Once the foliage has turned yellow and dried up you can cut it back for autumn.
- You have a maximum of three months for harvesting asparagus each year, make sure to not let the spears grow too tall or they will be woody and disappointing.
- Disease can build up in an asparagus bed, so make sure to move it around your site.
- Your asparagus can develop brown and yellow patches where asparagus beetle has invaded. Burn old stems before winter sets in. This way it will kill off the larvae of the bugs. This is heartbreaking in the second year.
- Slugs and snails can leave a trail of destruction behind and are prone to eating the tips of new spears. This can literally destroy two years work in one evening.
- Asparagus is very temperature sensitive and can die in a frost, so make sure to use a fleece to protect until around May time.
So after three years of protecting from weeds, slugs, asparagus beetles, frost, watering, feeding and mulching as well as protecting from the wind you then have three months to harvest when the spears are 7 inches and no taller. Leaving about 1 inch in the ground. This really needs to happen about once every two to three days as the spears will grow thick and fast when they do take off.
Asparagus is not for the novice gardener and even more experienced homesteaders think twice.
Carrots – Voted Hardest Vegetable By Allotment Holders!
I did a ‘little’ poll of around 23,000 online allotment holders and we had around 60% of the responses come back with carrots as the surprisingly hard veg to grow. A humble vegetable that is relatively cheap to buy in supermarkets, but a real trickster to grow. Here are our tips;
- The biggest issue with growing carrots is the soil is not suitable. Any stones or a heavy clay will result in your carrots being stunted or split. We recommend using sand mixed in with peat free compost in a raised container.
- Carrot blight is a heartbreaking situation as you will have got so far with your crop before it emerges. Helene R. Dillard, Department of Plant Pathology, At Cornell University has identified three main types of carrot blight and how they can impact your crop. Blight is likely to occur in hot or humid weather so the warmer States are not immune to this disease.
Cauliflowers Are Surprisingly Hard To Grow
Temperature coupled with a long growing season make cauliflower one of those veg that your grandparents may have grown, but our hot Summers now can kill off. To start with, healthy and well fed soil is essential for cauliflower and all brassica plants. A sheltered spot with good drainage but a wetter soil is preferred. When we spoke to the surveyed gardeners and agricultural workers the biggest fear with brassicas was the total annihilation almost overnight from cabbage root fly. Attacking the plant and noticed mainly by the wilting of leaves, this can kill young plants soon after they have been transplanted.
Next in line to eat your cauliflower before you is the cabbage white butterfly. This pest really can eat your entire crop in one day. Netting will help to keep them in check, to an extent but we have anecdotal evidence to suggest that even the smallest of holes can allow them in. Now you have netted in the slugs and snails who love the wet soil and brassica leaves.
Clubroot is a nasty little disease that shows up with wilted leaves and reddish brown edges. This can be impossible to remove and you will need to burn any affected plants and deploy adequate crop rotation.
The final little bit of extra difficulty with cauliflowers specifically is the need to blanch the florets to get those lovely white mounds. To do this you will likely need to tie the leaves up and around the heads about three weeks before harvesting. Not hard if you have garden twine and a gentle hand, but if your leaves are half eaten by slugs it can be a fruitless task.
Celery Is One Of The Hardest & Least Rewarding Veg To Grow
Celery loves free draining but wet soil. It is hard to grow as it needs to be blanched before harvesting. Celery also needs a cool growing period and when you consider that it takes between 150-180 days until harvest then you are pushing it to find a suitable spot in your garden – even in the UK! Daily watering as well as protection from frosts means that the ultimate growing time is hard to predict and knowing when to plant out is a real waiting game.
There are many easier options to grow that are a great alternative to celery, like lovage!
Salad Onions / Spring Onions – Difficult To Bring To Harvest For Beginners
I was initially surprised that so many people had come back to us with salad onions as the hardest vegetable to grow. However when you look at how much watering they need alongside soil and space requirements and warmth, as well as frost protection it becomes clear. Spring onions are one of those vegetables that just needs the right spot and to be transplanted at the right time to then get about 12-16 hours of sunlight a day!
Really the issues with spring onions can be overcome by garden planning and companion planting. Your biggest fear with salad onions is onion leaf blight as this is your main crop, rather than the bulb. Prevalent in wet and humid conditions, so basically during the harvesting period! With brown onions a little bit of leaf blight will be unsightly but more or less fine and you can harvest the bulbs and store them adequately, with spring onions it is pretty much game over. So rotate your crops as the blight can live in the soil and really build up during overuse of alliums in one spot.
Sweetcorn – Why It Can Be The Hardest To Bring To Harvest
I once turned our entire garden over to sweetcorn when we rented in Mid Wales. My husband was skeptical but I had faith in my spacings and that they would all pollinate. However we managed to harvest a clear dozen or so sweetcorn and they were nearly inedible. Here’s what that experience taught me.
The wind will pollinate your sweetcorn with each individual kernel needing to be pollinated to become sweet corn. So this can be all about how close you space each plant as much as the wind. So to avoid disappointment you must transplant healthy and viable seedlings to their final spacings.
You also have smut disease and Stewarts disease to contend with. Along with corn borer, corn earworm, and flea beetle who would all like to eat your corn before you. There is problems with the frosts and protection, high winds and overly hot days with too little in terms of rainfall.
Not for the new gardener and not for those with limited space either. Sweetcorn can be very disappointing as it looks so good for so long, until it doesn’t and then you have no harvest. I will be honest during our online survey, this crop got a lot of hate for basically looking all good right up until the day of harvest. Not to mention birds and mice or rats coming to eat your crop, that got a strong mention as well!
Sweet Potato Is Not Easy To Grow
You may be able to grow potatoes that are more native to the UK and more temperate climates and zones. Sweet potatoes are a whole different challenge.
Two main problems with growing sweet potato in the UK or colder Northern climates are the soil temperature and water levels. A tropical plant, sweet potatoes need both humidity and warmth. 100 days of warm sunshine to get a crop, however failing to keep the soil moist during this time will mean cracked sweet potatoes when you come to harvest.
A mulch is a good way to keep soil a little warmer, as is growing inside a poly tunnel or green house.
Wasabi (Japanese Horseradish) Has Been Voted Hardest To Grow
Now we grow horseradish in the UK just fine in pots, but Japanese Horseradish really needs different conditions altogether. Also did you know that when you are ordering wasabi it is highly unlikely that you will be eating true wasabi rhizomes? Instead it will be ground horseradish.
Grown commercially in hydroponics where the temperature of the water can be kept between 55 and 64 degrees, where the hours of sunlight are limited and the humidity and nutrient content of the water can be strictly controlled. Now I love my hydroponics, but even I don’t control water temperature and humidity to this level. Well not for one year and three months, which is how long wasabi takes to grow to maturity for harvest.
With wasabi it is all to replicate the area of Japan where it grows wild near to shaded and cool streams in a high up mountainous region.
What Vegetables Take The Longest To Grow – And Are Therefore The Hardest!
Asparagus takes between 1-3 years from planting crowns to harvesting or up to 6 years if you are planting seeds. Luffa will need between 120-150 days of warm sunlight. The growing conditions can make a longer growing period seem impossible in your zone. Wasabi takes 15 months to grow to maturity and under some very expensive to replicate conditions.
Conversely, garlic will take 150-210 days from planting to harvest, but as it is a great crop for overwinter we can leave it to grow in well drained soil and return for a Spring harvest. As long as it is well watered in the first few weeks and there is good drainage it is very much a case of sowing and walking away.
What Next & Further Reading
Learn to work with your garden and soil conditions! The hardest vegetables for me to grow in the UK may not be the hardest for you if you live in California. Texas will have different struggles to a garden in Italy.