I live in Hawaii. I put in a new raised garden this year in the middle of my yard. There is good air circulation, nice breezes and full sun, plenty of water. I spent a crapload of money buying good soil because there is no soil here. But nothing will grow. I don't understand why.
I use fresh seeds, many varieties. The garden soil is comprised of about 10% topsoil, 50% organic garden soil mix, 20% compost with steer manure and 20% purchased and homemade compost. The only thing that does well is my onions planted from bulb. They are very happy. Our pineapple tops are growing. Melon seeds will grow and then the plants start making crazy flowers all over when the plant is only 10 inches tall. They put out little melons which start, then turn yellow when they are 1 inch wide, fall off and die.
Most seeds won't even start and the ones that do, come up and then do nothing. They usually don't even put out a first leaf. They just sit there being green and not doing anything for weeks.
When I dig down, I feel a nice, crunchy root system, but can't figure out what's growing from it. It isn't grass. Also, when I dig down, the soil is all white and powdery. I assume this is mold. Plenty of mushrooms are growing as well, just no plants.
What could be going on? And should I be picking all of the blossoms off of my melons until the plants are nice and big?
Hmmmm....something is up with that soil. Not sure.
Are there any trees in the vicinity? Small rootlets can be creeping in from huge distances, depending on the species. Locally, locust trees can travel huge distances, and a tree cut waaaay down the block resulted in its roots sending up suckers in my friend's yard. The fact that your soil is poor and you added a small section of yummy goodies is a beacon to every hungry root around.
ETA: It could very well be that these roots are drawing huge amounts of water away from your bed. It could also be the mycelium from the mushrooms is making a mat in the soil that is shedding water. It happens.
The white powder and mushrooms mean that fungus is setting up shop and means that you have a high amount of carbon in the soil you put down. This should correct itself once the carbon levels drop, which is happening constantly. But it could be a culprit with what's happening this season. I wouldn't do anything about this.
"Topsoil" in the landscaping industry is just dirt, pure and simple. You are thinking it is what farmers call topsoil and it is anything but. "Topsoil" can be the initial scraping from development, excavated dirt....anything. It is used as a base to thin out some of the stronger ingredients like steer manure. It gives the soil bulk and minerals and drainage. And cheapness! That dirt can come from anywhere, and I would be suspect if I had trouble that could be a culprit.
That said, the amount of topsoil vs. compost in your mix seems a bit low. If I were topping a half-decent native soil, I would use no topsoil, but that would assume using the native soil. If there was no soil, then you can't do that. You have to assume you are planting on something slightly better than concrete and you need plain soil to keep the mixture from being too rich.
Yes, we grow stuff in straight home compost, but most home composts are made of yard waste and food waste, not from vast amount of manure, and the relative coolness of it vs. commercial compost keeps the material lighter with more air circulation and drainage.
"Steer manure" and any other animal manure or compost mixed with it can contain clopyralid, a preemergent herbicide used in grain production. It survives the animal's system (also horses, if you use horse manure, even in chicken manure) and can produce "toxic compost". The symptoms are some of what you are describing: a seed might sprout and just sit there, or it won't sprout at all.
Melons and squashes will produce male and female flowers. The males do drop off, and it can be dramatic because a plantcan produce 5x the number of males as females. Check where the stem meets the flower. Females will have a tiny, unfertilized fruit at the base, males will not have this. Also, the lack of proper pollinators might give trouble.
But, if the flowers are getting pollinated, drop-off can also happen when the soil is way too rich, especially with nitrogen. It doesn't sound like the cantaloupe had the proper cultural needs. Which one that is, I can only guess.
In fact, it's all just a guess. Nothing stands out to me. On first glance, the soil mix sounds too rich. A typical mix might be 1/4 topsoil, 1/4 sand, 1/4 commercial compost, and 1/4 composted manure/sawdust mix. That's a standard, fairly rich landscaping mix.
Give me a few minutes while I caffeinate.
Thank you for all of the help!!
No, it couldn't be tree roots. We do have a pine tree and several acacia trees outside the property, but the roots would have to grow very, very far to get to the garden. There are some baby coconut palms a few yards away, but that couldn't be it, either. I made slightly raised beds by putting down thick cardboard to keep weeds from coming up and then I put the boxes over that and then all of the soil mixes. And the whole garden isn't but a couple of months old.
Also, the soil is very, very moist. It holds water well and we get rain every single night so I know the plants have more than enough water. We live in a rainforest.
I'll see if I can add some more topsoil. I put very little in. My friend has her plants growing right out of her compost pile, so I didn't realize plants even actually needed soil. Topsoil is VERY EXPENSIVE here. It has to be shipped from far away because soil is hard to come by in Hawaii. Our islands are so new that the soil is very shallow or it just washes away with all of the rain. The island is mostly just rock. But we can grow grass on the rock. :)
I will add topsoil. Mahalo!
You can also try adding some course sand. And patience. Wait this out and I think things will be better once it has a chance to "cool" down a bit. Yes, home compost grows some good plants, but you wouldn't add steer manure to it. If it is just the manure-and-compost making things difficult, waiting awhile should correct things.
Since you bring up the rainforest, and the plants getting "more than enough water", that could be another issue, especially since you haven't added sand and very little "topsoil". Also, cardboard at first can act like a barrier, causing water to collect at the bottom and make it far too wet. In fact the more I think about the situation, the more I wonder whether the culprit is drainage? Dig down to access all levels of your bed and squish the dirt, get a feel for how much moisture it is holding.
Also, this is a no-brainer, but I mention it anyway. Make sure your seeds are developed for your area. I know Hawaii has several climates--make sure your seeds are bred for your rainforest conditions. I'm curious, what pollinates plants like cantaloupe there? It's bumblebees in all my home gardens. What kinds of bees do you have there? (I'm sure they would love the acacia!)
The wetter the conditions, the more sand you should use when you are mixing soil for new beds. You can practically go up to 50% sand in some cases. A home compost, is raised far off the ground (sometimes 3 to 4 feet) which offers great drainage despite the lack of sand.
Give me a few minutes while I caffeinate.
I got my garden soil mix form a local company. I put it in the raised beds last August. Everything rested over the winter (except the garlic bed), and I planted in the spring. Later when I went to a local organic gardening center the owner asked how my garden was doing. When I said "great!" He was very surprised. Apparently lots of people get the same garden mix that I do, fill up their boxes in the spring, plant, and have bad results. My thought is that the high amount of organic matter in the soil needed to compost in place over the course of a season, and then it was ready for planting.
It has only been a couple of months. It could be that it's all still too new. I'll put in some more soil and keep trying and hopefully things will even out at some point.
You might consider getting your soil tested if you have a local cooperative extension. You can find one at www.csrees.usda.gov/extension. I see Hawaii is on the map.
Take a look at your pH levels and NPK ratios. Different veggies do best with pH levels specific for that veggie (acidic vs neutral vs alkaline). You can find a list of what veggies require what pH level on the Internet. And you can find what to do to adjust pH as well.
But I would start with the NPK ratios--the amount of nitrogen, phosphorus and potassium in your soil. Look here for a simple description of what each nutrient does: http://www.gardeners.com/fertilizer-basics/5161,default,pg.html
Nitrogen produces green growth. So maybe your nitrogen levels are too low. That would tell you why the green parts of the plant are not growing. Phosphorus is for root growth, buds and flowers (or fruit). Potassium is for disease resistance and overall plant helath.
If any of these nutrients are too low, you can add to them with organic fertilizers.
Also, there are some great garden forums out there with experienced gardeners who can answer questions like these. I would try some of those. And your local colleges might be able to help if they have agricultural programs.
I wish you good luck! Keep us posted!