How to Improve Unhealthy Zucchini Plants

Discover how to improve unhealthy zucchini plants from the garden with rot.

Share with a Friend...

Growing Zucchini

I’ve been planting zucchini since I was a kid and always enjoyed the versatility of this vegetable.  My favorite would be harvesting to grill with chicken and I also like fresh baked zucchini muffins.

The last couple seasons I’ve had difficulty keeping zucchini plants healthy.  This year it happened again, the green leaves went from yellow to brown and parts of the plant looked like somebody sat on them.

Instead of getting frustrated I decided to tackle these issues before giving up and ripping out the entire plant. To do that I had to get my spring planting notes for details.

  • I planted Italian zucchini seeds in a new area and bed in April.
  • Growth was quick with limited harvest for one plant.
  • When June arrived, it looked like this plant and harvest had been through a war.

Possible Factors

  • We’ve had more rain than normal – I’m calling it crazy rain!
  • This was a new bed and the soil could be lacking nutrients.
  • I was late getting mulch applied.
  • I’ve been very hands off this year which could be the biggest factor of all.

Stages of a Zucchini plant

What Causes Yellow and Brown Leaf’s?

  • Culprit Number #1 – Excessive watering
  • Culprit Number #2 – Root Rot Infections
  • Culprit Number #3 – Soil Fungus also known as verticillium wilt and fusarium wilt

I looked at these factors and because natural gardening is my preference I took a step back and watched this plant for about a week.  I also stopped watering between rainfall and covered the bed with hay mulch from our pastures.

Then I removed all the brown and yellow leaves with clippers by cutting them from the base.  At this point the plant was growing in three directions and it was only a matter of time before the growth had the ability to go explosive.

Growing Zucchini experience

What was Going on?

I looked over the entire plant including the leaves I removed seeking squash bugs, insect eggs or anything bug related that could be causing the problem and nothing was apparent.  I ruled out the soil because on the opposite side of the garden cucumbers were growing with the same new soil base and they’re doing great; the only difference is I planted the cucumbers in May.

Cucumbers, zucchini, pumpkins, melons and squash fall under the same family tree, Cucurbitaceae. Many times, when I’m researching problems I’ll compare their activity.

I went back to the excessive watering, which I couldn’t do much about because it was falling from the sky.  However, I stopped watering during my watering schedule and let the soil dry out between rainfall and things started to change.

Growing Advice for Revamping Zucchini

Then I Clipped the Plant Again

After that week of inspection, I drastically clipped the plant leaf’s back a second time towards the base, including the good ones.  Beginning from the center and even removed one of the long extensions so I could inspect things deeper.

Again, no bugs were present and everything green I removed was really healthy.

By removing all that weight and backing off on my watering the plant began to grow again, which made me realize the soil was good.

The hay mulch helped maintain the rain water which was another advantage because our temperatures began to rise several weeks ago.

Learning about Zucchini failures

I burned the debris and there was a lot, then made additional notes in my garden planner.  Looking back, it was easy to see that rotational planting was a good choice from the beginning as it helped me rule out common pest problems.

I’ve mentioned many times on the blog that gardening offers the opportunity to learn new things all the time.  It’s also about never giving up, never accepting failure and learning as you go because we can gain wisdom through research.

That’s one of the things I love about planting a garden it’s full of lessons that make us better people.


New Crop of Zucchini

New Growth Populated

After removing expired growth; this plant was left to rest and rebirth new life; it’s now producing a healthy harvest.  This happened because I didn’t accept failure and I saw an opportunity to learn by staying true with an all-natural gardening system that really does work.

I don’t believe gardens are supposed to be filled with perfection all the time, it would be great but not realistic.

Sometimes when we remove our failures we forget we’re removing an opportunity to gain knowledge.

Improve the garden you love so dearly and let your soul flourish through the process, it’s absolutely amazing.



Growing Zucchini

Share with a Friend...


  1. Charlene says:

    Thanks for the info. I started cutting old brown leaves off of my zucchini and yellow squash today. Usually I have every plant that is infested with the borer. So, I suppose tomorrow I will cut off the rest of the horrible foliage and see what happens.

    1. Carole says:

      You can save that zucchini just clean it up and maybe add some mulch around the base too.

  2. Rhonda Avery says:

    Such a great info..I have blossoms and small zucchini now but they do not seem to be growing very large…I have limited space and am growing cukes in pots wich are doing well. I am going to trim some of the dead zucchini leaves and see if that your ideas!!

    1. Carole says:

      Thank you Rhonda for such a nice comment… Yes do trim those dead leaves because it really does help. Not sure where you live or when you planted but it’s still pretty early in the season. Our weather has been crazy and as a result my garden is off to a slow start. You can trail those cucumbers up and off the ground too which looks really neat. THanks for sharing… Carole

  3. Tracy Lynn says:

    I have never tried this, but it does make sense! Out with the old and diseased so the new can grow and flourish! Going to give this a try on one of my plants and see. Thanks so much! I am so glad I saw this on the Our Simple Homestead Blog Hop!

    1. Carole says:

      You’re welcome Tracy hope it works for you.. Process of elimination always helps me…

  4. Karen says:

    This is a fantastic article! I love how you walked through a trouble-shooting plan to find the source of your problem, then worked on solutions. Having those written notes available was crucial, wasn’t it? Just another reason to make sure we’re writing things down because we’ll never know how important even the smallest details can be in the future of our gardens. And I’m so glad I have a copy of your gorgeous garden journal to keep my own notes in now! 🙂

    We’ve had a lot of rain here this summer too. I’ve enjoyed it because it has drastically cut down on the watering I have to manually do. My main raised bed area gets watered from a well-fed source, but the potted plants on the deck and my herb garden are closer to a municipal water outlet and sadly, that isn’t the most ideal water for growing plants. Having a lot from the sky this year has not only lightened my work load, but given them a generous supply of “good” water too.

    It’s been a few years since I’ve grown zucchini, but I sure know what to do in the future if I have similar problems! Thanks for sharing your expertise.

    1. Carole says:

      Thank you for coming by to share such great insight. I completely agree about the garden book – it really does make all the difference and I’m glad you found the planner pages helpful. The rain…. I agree it’s lightened the load for watering and does contain some awesome amounts of nitrogen too. Not sure I’ll be growing zucchini next year but I will tell you it’s in a 2 x 3 raised bed and devoured that space. Little Startle Garden Wow factor!!

  5. Lynn Spencer says:

    Hi Carole, for the first time in a LOOOONG time, I actually still have zucchini plants in my garden…typically by this time the squash borers have killed them. So…that’s a good thing…but the ones I do have haven’t produced a zucchini yet! I’ve been gone for a week, but think I’ll give it a good dose of fish emulsion to see if that wakes it up.

    Like you, I am an organic gardener so understand the thinking of identifying the problem instead of just bombarding the plant with chemicals.

    Thanks for the insight.

    Hugs, Lynn

    1. Carole says:

      Good Morning Lynn – You know I’m almost ready to give up on growing Zucchini because of those squash bores myself. Haven’t had issues with them this year and I really think it’s because I plant them in a new spot each year. This year though I went a great distance from the last growing season. The perks of a large garden but man can I hardly wait to scale down. Anyways for those non producers you might need to introduce those male and female blooms. A friend showed me this one time to help increase with harvesting.. I just kind of looked at her weird but it did work. Fish fertilizer is great – was a favorite of my grandmother.. I use what we have around the farm.. No chemicals here and it’s so awesome especially when hummingbirds come to visit. They slow down and stay for awhile, which hopefully one day I’ll get a few photos of them. Have a Great Thursday, Carole

  6. mickie mclaughlin says:

    Thank you for getting back to me……plant looks healthy in every way…soil is made up of garden soil, chicken manure compost added last fall, and a bit of sand. The other two plants seem to be doing great. My free range chickens keep the bug population down in the garden area. We’ve had sporadic rain fall with a ton of rain the last three or four nights. Any other ideas? thanks Carole. mm PS is it too late to plant seeds again.

    1. Carole says:

      You’re welcome – I enjoy helping.. If all your other plants are doing fine and don’t have any similar issues than I’m going to suggest it has to do with the additional moisture. Check the drainage and test the soil moisture prior to watering next time. Really sounds like that last down pour activated these issues. I didn’t realize you had chickens, I love their help with the bugs. Check your first frost dates before planting again, if you’re frost doesn’t arrive until late October or November you might be able to swing it. Just make sure you plant in a new area. Hope that helps and the only other thing I’m thinking it could be is herbicide contamination, which is basically pesticide from manure if animals have been eating treated hay. I really don’t think it’s that because you mentioned the plant turned after those three nights of rain.

  7. mickie mclaughlin says:

    Hello Carole….How did you know I was dealing with this issue today. I will be trying your suggestions. When I looked at my three plants last weekend all looked healthy and two had blossoms on them, so I presume they will eventually become zucchinis. However, one plant had only ONE developing blossom on it. Fast forward to this morning and the fruit on that plant seems to be deformed. The end nearest to the vine is quite small while the far end is a big fat short fruit…..not at all the long zucchini I was expecting to grow. What causes this? I am so looking forward to trying the zucchcini spirals and, of course, making bread and muffins. mickie

    1. Carole says:

      Hello Mickie – Those muffins are the best aren’t they – try making them with Oat flour, they’re even better. Okay to your plants… Investigate and first try to detour if this is bug related first. You can do this by checking the stems and leaves but inside that vine is another good place to check. Now if you use any type of chemicals for bugs or purchase treated mulch there could be a whole new issue going on. Which I don’t want to scare you so before I dive into that discussion investigate a little more so I can help you better. -Carole

  8. Jemma says:

    Hi Carole,
    Great gardening tips as always!
    Such an odd year with all of our rain and then the other day we even had more.
    I think we are moving through Summer quite nicely:)
    Have a fabulous afternoon!

    1. Carole says:

      Hi Jemma – Well it’s been raining here every weekend and then some since May.. Agree it’s been a strange planting season..
      I didn’t plant much this year – just didn’t have it in me.. Wanted to focus on some specific things instead of approaches the masses. I think I’m after Tiny Gardening too!
      Hope you’re having a nice afternoon too – I’m kicking back for a change.


  9. Patti says:

    Hi Carole,

    Great post. I love the idea of comparing your zucchini to the cucumbers. Not only because they were in the same bed but also the same family. Great tip. I think most people including gardeners have problems with over-watering. Myself included. You idea to cut back seems to be a great solution and hey, it’s less work for you. I’m sure many people reading this will take comfort that we all have problems and your step by step analysis is a great way to learn and figure things out.

    1. Carole says:

      Thank you Patti – the watering in conjunction with the rain really was something. It get’s windy here and things dry out fast so I didn’t really think the additional was messing things up. I love comparing plants in the same family, maybe I’m a garden geek… LOL Just something that seems to come natural after spending so many years gardening.
      Have a great day and thanks for stopping by to share.. Carole

  10. Courtney says:

    Great post! Our zucchini has struggled that past few years with vine borers, and this gives me motivation to keep trying.

    1. Carole says:

      Good Morning Courtney, Make sure you’re planting in a new spot every year, that’s a really big deal and think about putting seeds in a raised bed if you haven’t already. Hope all is well and your enjoying summer- it goes by too quickly.. Carole

  11. Susan M. says:

    This is so logical! I’ve had problems with Zucchini the last few years. Cutting the damaged leaves and a few extras probably allows the plant to use it’s energy producing the zucchini, rather than deal with dying leaves. Plus, it looks better! Thanks for the tips!

    1. Carole says:

      Hello Susan – Logical yes but to many times we just want those problems to go away so we rip out and move on. Love those lessons we learn in the garden. Hope you have a great week!

Comments are closed.