KH6OWL
Newly Registered
Posts: 1
Joined: Tue Feb 07, 2017 7:09 pm
Location: Kapolei, HI

Soil Issues

Alright, here goes.
In Hawaii and the soil is not very good. I do 100% pots and raised beds. I have tried numerous options for soil in bags at the big box store and soil from a soil company that stated it was the best they had for gardens.

The soil has high PH and once it gets wet it becomes very compacted. The only thing that grows well is Pineapples, bananas and papayas.

I'm trying to grow potatoes and they are supposed to be easy. Carrots, lettuce, anything you can eat really. I have tried it all.

I need some good soil and can't seem to find the right fit. I have tried mixing Perlite, vermiculite, Peat moss, chicken manure and some compost.

Any advice would be appreciated. I've almost given up growing things.

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ElizabethB
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Posts: 2105
Joined: Sat Nov 24, 2012 12:53 am
Location: Lafayette, LA

Welcome to the forum.

My experience with SFG and other container gardening has been successful using a mixture of 1/3 well cured compost, 1/3 peat and 1/3 horticulture vermiculite.

Hopefully Imafan will chime in. Imafan is from Hawaii and is a successful gardener.

You may consider setting up a couple of compost bins.

Don't give up yet.

Good luck.

ButterflyLady29
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Posts: 1030
Joined: Mon Oct 19, 2015 9:12 pm
Location: central Ohio

Can you get coir fiber or crushed oyster shells? Oyster shells might help balance your soil ph.
Coir fiber has done very well for me. It keeps the container mix light and prevents compaction. It has no nutrients so fertilizer is essential.

imafan26
Mod
Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

There are 12 soil series in the island but mostly they breakdown into about three
High elevation and red dirt= Oxisol acidic, highly eroded and high iron and aluminum generally nutrient poor but grows well with fertilization. Heavy soil should never be worked wet.
Near the beach and sandy = beach conditions high calcium floods when it rains very hard
Tantalus grey rocky soil= very fine and eroded
Parts near Lualualei Naval Road= expansive vertisol very fertile but expansive so hard to work
Pearl City / Pearl Harbor = molisol sticky soil very hard to work.

If you live in a high rainfall area like Manoa, Kaneohe, Wahiawa, or Mililani the soil is red dirt and more than likely on the acidic side unless it was heavily limed in the past

If you live near the coast, you have a lot of coral so the soil is hard, literally rock and very alkaline. Coral is hard to dig through and when it floods it does not drain well. The soil is saline especially within a mile from the beach.

If you can grow pineapples, bananas and papaya, your soil is not that akaline naturally, and unless you are watering like mad you are unlikely to be living in Kapolei since the papaya and banana likes a lot of water and a fairly deep soil.

If you have established your raised bed. I would get a soil test. The following is a handout from UH on how to collect a soil sample. You may not be amending it with what you need or in the proper amounts. If your soil is truly alkaline and you are using an alkaline compost, chicken manure will only make it worse.
https://www.ctahr.hawaii.edu/oc/freepubs/pdf/SCM-9.pdf

Label the bag with your name and phone number and take it to any of the extension offices. Urban garden center in Pearl City will take the soil sample during the week. The secretary will help you fill out the paper work. A pH and major nutrients cost about $12 (in 2016). It takes about a month to get results but you will get the results in the mail. It will tell you the pH and the major nutrients and also give you recommendations on fertilizer and to correct pH if needed based on 100 square ft. If you don't understand the results you can call or email the master gardeners to explain it or go to any of the MG at the local open markets. Every second Saturday, the next is Feb 11 (9-11 am) the master gardeners will have a booth at the Pearl City urban garden center. You can ask for advise there. They usually don't accept soil samples on Saturday, the office will be closed. The garden is open M-F 9 am -2 p.m. There is a new garden topic every month.
https://www.ctahr.hawaii.edu/ougc/

I grow a few things in pots as well as in the garden. I get a soil test about every three years to see if I need to make adjustments. I have three gardens. Two are alkaline and one is acidic. In the acidic garden I grow tomatoes, cucumbers, gardenias and roses. In the alkaline gardens, I grow cabbage, greens, herbs and squash.

I do grow things in pots. I use large pots 15 gallons, tree pots (25 gallons), and muck buckets (because they are cheap but they are not UV resistant so they don't last that long. If you grow in pots, go large, they will have enough root space and they don't dry out as fast. They still fall over in the wind. SIP containers also work well for plants that need a lot of water like tomatoes.

I always bleach my pots after I clean them out. Reusing the potting soil has not gotten very good results and it is cheaper for me to replace the soil than soil test them. I resterilize the potting soil and use it in my garden. I use Miracle grow potting soil (make sure it is not moisture control or garden soil. Garden soil is too heavy and moisture control will kill everything when it rains for a week).

Sometimes I make my own soil mix for pots. One part peat moss, one part perlite ,a handfull of vermicast if I have it (no compost of manure, only vermicast has not caused problems), and about 1/4 cup of osmocote. This mix drains well and I can water everyday and it won't cause issues. If you don't water that much or your plants dry out too fast you can use 2 parts peat moss and one part perlite instead. I do not use coir or vermiculite. Vermiculite is a lot more expensive than perlite and coir is too wet when it is wet and dries out unevenly. It is good if you have plants that don't mind drying out between. It packs densely.

You can also get sunshine mix #4 which is a ready made potting mix sold by BEI, CPS, Or Pacific Ag. It is comparable to a 50/50 peat lite mix.

I buy 4 cu ft bags of perlite and 3.8 cu ft bags of peat moss from Pacific Ag or Crop Production Services (CPS). I call first they run out of perlite. Then I have to buy the sunshine mix instead. I also buy osmoscote in 50# bags. It is not cheap but cheaper then buying smaller bags and one bag can last me a couple of years. I don't want a lot of bags of different fertilizers around so I use citrus food (vigoro from Home Depot) 6-4-6 or Expert tomato and vegetable food 9-12-12 in the pots. The point is I use low numbers. High numbers is not necessary.

I usually start my seeds in community pots and transplant them out. I use the peat lite mix for seeds. I don't band fertilizer, I found I had a lot of unused fertilizer in the pots that way. I will add 1/2 cup of the citrus or tomato food (whatever is on hand) and mix it into the pot of soil when I transplant the seedlings. If I am direct seeding the pot, I will not fertilize until the true leaves come out. The seed has all the nutrients it needs until then. I usually only put one tablespoon of fertilizer when true leaves appear, and repeat fertilizer at the first flower, first fruit set, and monthly thereafter (if I remember).

Make sure the pots are evenly moist when you plant either seeds or seedlings.

Don't crowd the pot.

20 inch pots = 1 citrus tree in pure black cinder nd fertilizer osmocote plus citrus food when the plants flush, flower and fruit.
In 18 gallon pots, I plant ginger, 1 tomato, 9 beans or peas, 1 eggplant
7 gallon pots chili pepper, rose. bay leaf
1 gallon pots, herbs chives, green onions
3-5 gallon wide pots taro, araimo
14 inch bowls spreading plants like mint, oregano, marjoram, and thyme
Root crops like carrots and beets do o.k. in the alkaline garden but don't make roots in my acidic garden because it has a much higher nitrogen content. Nitrogen is not directly measured on the soil test, you have to submit a leaf sample at the same time as the soil to determine adequacy of nitrogen. My plants are huge and the root crops produce a lot of foliage and not much roots, so I know it is high in nitrogen. If I want to grow beets in my acidic garden I have to grow them in pots and add some dolomite and use bulb food. Citrus food contains sulfur and I use sulfate of ammonia as my main source of nitrogen.

My alkaline garden had a pH of 7.8 which went up from 7.4. I added sulfur and peat moss instead of compost. The only other thing it gets is citrus food (acidic fertilizer)

My acidic garden has a pH of 6.0 (down from 6.4) which is perfect for my oxisol. However, since I use sulfate of ammonia for Nitrogen, I added some dolomite lime to keep it from dropping further and I am using Kellog's N'rich and Amend for the compost. I like black gold, but it is hard to find. I till in garden residues and I do some trench composting.

All of my plots test high or extreme for phosphorus and high for calcium and potassium. I only need to add compost and nitrogen for another couple of years. I could add chicken manure to the acidic garden to bring the pH up a half a point.

In my acidic garden I grow corn, cabbbage, Asian greens, cutting celery, cucumber, green onions, chives, kale, broccoli, herbs, (mostly plants that need high nitrogen or are leaf plants.) I grow tomatoes, eggplant, and peppers in pots since they take up too much space in the garden.

In my alkaline garden I grow cabbages (they don't mind alkaline conditions) roots crops like carrots, beets and daikon. Squash, gourds, peppers, chard and lettuce (I have fewer snails in the alkaline plots.)

Carrots will only grow well in the cooler areas in the cooler months. They like to be less than 75 degrees. They will grow at other times but they are much more bitter. Nelson and nantes are the better varieties. Danvers grows well, but doesn't taste very good.

I only grow sweet potatoes, they are easier than potatoes since they are tropical in origin.
Try growing peanuts and jicama they need a long hot season and are good in pots.

Slugs and snails really love lettuce.

Try growing tropical veggies instead of temperate ones. Temperate veggies grow best on the mainland but we have to grow what is easy for us and those would be heat resistant tropical varieties

Araimo, daikonwhen your bed is adequately fluffed. I don't think you have enough compost in it if it is still hard.
Beets can be grown year round and they like slightly alkaline and lower nitrogen soils, they come out of the soil as the bulbs form and they need to be side dressed just before the bulbs start to form.
Asian greens like cool weather. October- April
herbs- green onions, mints, cilantro (cool weather), culantro like an evenly moist soil in morning sun. Basil is hard to grow because of basil downy mildew.
Lavender, sage, thyme, oregano, marjoram will require well drained soil in full sun.
Sunflowers, squash, beans (use local seeds from Aloha Aina or UH for rust and nematode resistance), gourds, watermelon, cucumbers, bitter melon, Chinese peas (cooler months). Tomatoes need nematode, disease and heat resistance. They are not easy to grow and not something you want to take on if soil conditions are not right.
Spinach has a short season, but NZ hot weather spinach can be grown year round. It is actually hard to keep up with it.
Hot peppers (cage them from the birds)
Bag fruit and put out fruit fly traps or everything will be stung.
Vines need a lot of space to sprawl.
Slug bait every two weeks especially when it rains.
Plant to attract pollinators and predators. You will need to inspect plants every time you water for whitel flies, aphids, scale, thrips and take care of things early. There is no off season for pests in Hawaii.

imafan26
Mod
Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Soils and composts are not created equal. If you have an alkaline soil, don't use compost from green waste. That pH is very alkaline. Use peat moss instead. Peat moss is limed to about a pH 6.0 and it will keep the pH stable longer than sulfur. Sulfur will also bring the pH down but it will need to be converted by the soil organisms and that is a very slow process that takes about 6 months to get the full effect. The soil test will tell you how much you have to add to make the correction. If it says to add compost to correct pH add peat moss instead. Peat moss is an acidic compost. Compost is not as neutral as many people believe.

https://menehunemagichawaii.com.s64416.g ... eet(2).pdf

Farmerboy
Full Member
Posts: 17
Joined: Mon Mar 20, 2017 9:54 am
Location: Southern Oregon

I make my own well drained potting soil. It consist of 1/3 Composted Manure, 1/3 Sand, and 1/3 Soil, then lightly cover the surface with wood ashes.
I use the same formula for soil in my raised beds.



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