Growing Zucchini Easily

Growing zucchini is really not hard and with just a few critical tips you can have flourishing plants and deliciously fresh zucchini straight to your table.

In this guide to growing zucchini I've covered everything you need to know that I learnt the hard way including :

1. When To Plant Zucchini
2. Growing Zucchini In Pots
3. Protecting Zucchini From Slugs
4. Preventing Mildew On Zucchini
5. Pollinating Zucchini

I've also got simple tips on how to grow zucchini vertically so you can enjoy them all season long in even the smallest of vegetable gardens.

I hope these simple tips help. For more easy gardening tips do follow me on Pinterest.

When To Plant Zucchini

Zucchini seeds need warmth to germinate which means waiting in some areas until May or even June to sow your seeds directly outdoors.

I have given dates for planting outside below but I always recommend sowing zucchini seeds in pots indoors 3 weeks before these dates to get ahead.

Zucchini Sowing Dates By Zone

Plant zucchini seeds directly outdoors  : 

• After last frost date in your area 
• When overnight temperature > 55f/13c
• Soil temperature > 60f/15c (pre-warm with cloche).

In different US & UK zones these temperatures usually translate to :

• Zone 3-4 : Late May - early June
• Zone 5-6 : Late April - mid May
• Zone 7 : Mid April - mid May
• Zone 8 : Mid March - mid April
• Zone 9-10 : February - March
• Zone 11 : Autumn - Winter
• Southern UK : Mid-late May
• Northern UK : Late May - June

How To Sow Zucchini Seeds

Zucchini are easy to sow in small pots and directly into raised beds. Simply : 

1. Sow seeds one inch deep
2. In rich planting compost
3. On their long edge not flat to reduce rotting.

For slightly quicker germination you can soak seeds in warm water for 8 to 12 hours but it is not essential.

How Many Seeds Should I Sow

You can easily end up with too many zucchini plants - taking up too much room - and way too many zucchini which don't freeze or preserve well.

But I always sow 10 seeds for backup as young zucchini plants are very vulnerable to slugs. Once a safe size - see further tips below - you can pass on spares in pots to neighbours.

Sowing Zucchini Seeds In Pots

Start zucchini seeds in mini biodegradable starter cells so you can easily transfer seedlings to larger pots without damaging roots.

Sow one seed per cell as they will need transplanting and roots can tangle.

Sowing Zucchini In Raised Beds

If growing in colder zones e.g. USA 3-4 or northern UK it helps to sow seeds in little mounds of soil 2-4 inches high.

The mounds will be warmer than the flat bed and drain better giving quicker and healthier germination.

Growing Zucchini In Pots

Growing zucchini in containers - it could be a pot, an old bucket or a grow bag - is great for the zucchini and great for the rest of the garden.

Zucchini plants need much more heavy feeding and deep watering - to avoid mildew - than most summer veggies. In a self-contained pot the zucchini can get the special care it needs.

It is also easier to protect zucchini plants in pots from slugs and snails.

Key rules for successfully growing zucchini in containers are :

1. Big pot > 5 gallon/22 litre.
2. Must have drainage holes.
3. Elevate pot on bricks for drainage.
4. Mix of rich compost & 30% grit.
5. Water well so moist throughout but do not drench until soggy.
6. Transplant 1 young plant per pot.
7. Mulch to retain moisture but not right up to stem to prevent rot.
8. Protect from slugs.

Your zucchini will be happier in a generously sized container. Grow bags are a good option if you are short on space as easier to store away in winter.

Feeding Zucchini

Many gardening experts recommend feeding zucchini plants every 1-2 weeks with tomato feed for bumper crops.

The problem with this advice is that most of us do NOT want a bumper crop of zucchini. You can only eat so much and it does not freeze well.

So if you don't need a huge crop and want to garden organically avoiding commercial feeds focus on the basics :

1. A generous sized container.
2. Great organic compost.
3. Consistent watering.
4. Regularly harvesting young zucchini to stimulate more fruit.

Number 4 is key because larger zucchini will drain the plant's energy and increase need for feeding. If leaves are yellowing at any point you can top up nutrients with wormery juice.

Zucchini On A Vertical Trellis

Fruiting plants that grow vertically like tomatoes, raspberries and peas are a god send in the small garden. You wouldn't think zucchini are in this gang but you can grow zucchini vertically.

You will need a heavy duty wooden or metal frame for support such as a :

• Tomato cage
• Cucumber trellis
• A-frame
• Metal pole
• Old pallet against fence
• Or even an ornamental arch.

Put your support structure firmly in place in the ground before planting out seedlings next to the support. To get your zucchini plant to grow vertically up the support you simply :

1. Tie main stem loosely and gently to frame once 3-4 inches tall.
2. Every 3-4 inches it grows tie again.
3. As grows can tie every 4-6 inches.
4. Tie under leaves to stop slipping.
5. Use soft ties not wire or string.
6. Once fruiting, cut off leaves below fruit so nutrients move up plant.
7. When harvesting zucchini, harvest leaves up to next fruit.

How To Keep Slugs Off Zucchini

Slugs and snails adore young zucchini plants. They can destroy all the leaves overnight with ease hence my tip to sow back-up seeds.

Luckily, zucchini plants quickly become slug resistant naturally. They develop prickly hairs on their stems and both stems and leaves become coarsely fibrous, both of which the slugs hate.

However, until your plants have acquired this protection - usually once they have 6 true leaves and are growing vigorously - you MUST protect them individually from slugs and snails.

I swear by copper rings backed up by these DIY natural slug repellents :

• Gravel & sea shell mulch
• Spruce & pine cuttings
• Bramble & rose cuttings
• Sandpaper
• Coffee grains
• Egg shells
• Wool pellets

Zucchini Flowers But No Fruit

Zucchini are easy to grow and will usually look after themselves but you may get unlucky and have lots of zucchini flowers but no fruit.

The 2 main reasons for no fruit are :

1. Only Male Flowers
2. Lack Of Pollinators

Only Male Flowers

Zucchini have male and female flowers. You can tell the difference quite easily. The male flowers - on the left - have a pollen covered stamen, whilst the female flowers - on the right - have a rather odd shaped stigma and a mini-zucchini ovary behind the flower.

The male flowers come first to attract pollinators so be patient but sometimes you just get male flowers. Possible causes of the problems are :

1. Weather Too Cold
2. Lack Of Sun
3. Inconsistent Watering
4. Poor Soil
5. Too Much Nitrogen

Weather Too Cold

Zucchini do need warmth and female flowers can be slow to appear in colder zones if temperatures drop in June after a good May. Be patient.

Lack Of Sun

Zucchini also love light. A grey June - not uncommon in the UK! - can again delay female flowers. And again you just need to be patient.

Inconsistent Watering

Zucchini will grow in wet and dry conditions but get very stressed by inconsistent watering. Highly stressed plants may persistently produce male flowers. Water consistently.

Poor Soil

Zucchini are heavy feeders and if you succession planted them after other heavy feeders the soil may just be too poor to support fruiting. Top up well with balanced garden compost.

Too Much Nitrogen

Zucchini need nitrogen - so good to plant after nitrogen feeders - but love balance. Excess nitrogen in feeds can generate lots of leaves but few female flowers. Feed with balanced compost.

Lack Of Pollinators

Zucchini depend on bees for pollination. Their big orange flowers do attract bees but the zucchini pollination window is very short - female flowers may only open for one morning - so you need plenty of bees around.

The male flowers that appear before female flowers attract bees but to really draw them in plant some of these :

• Borage
• Sweet Alyssum
• Nasturtium
• Calendula
• Marigolds
• Bee Balm
• Zinnia
• Yarrow
• Phacelia
• Chamomile
• Sunflower
• Catmint

If you are struggling to attract bees you may need to carefully hand-pollinate your female flowers.

Hand Pollinating Zucchini

It is actually pretty easy to hand pollinate zucchini simply :

1. Get outdoors early morning when female flowers open.
2. Use a small soft kids or artists paint brush or a cotton bud
3. To pick up plenty of pollen from the male flower
4. Then brush the pollen into the stigma of the female flower.

How To Get Rid Of Powdery Mildew On Zucchini

Powdery mildew is a not uncommon problem with zucchini. You can treat the mildew organically by :

1. Removing infected leaves.
2. Spraying leaves with a DIY anti-fungal remedy.

But the most common cause of powdery mildew on zucchini is plant stress and not as you might think, or have been told, over-watering

So whilst removing infected leaves give your zucchini plants some TLC :

1. Remove old outer leaves if new foliage coming through beneath.
2. Thin leaves out further if necessary to create better airflow.
3. Water consistently - don't go from drought to drenching.
4. Water deeply - if you water little and often the moisture will just evaporate into the air and get trapped by the leaves
5. Feed your beds with well balanced compost.

And there you go, everything you need to know about growing zucchini easily. Do shout if you have questions.

For more gardening tips check out my other Grow Your Own tips.