any good recommendations on mixing your own or what amendments to add to bagged "soil", which really seems like majority wood product? I want some thing light and fluffy ,but end up with soggy and clumpy.

I have been using kellog soil in the pink bag and not really thrilled. I mix anywhere from 1/4 to 1/2 perlite because it compacts pretty bad over time. I have never really like the results though. It just seems bland . I also use hydrolyzed fish to feed. Check the PH of the soil with a cheap tester I have anywhere from 7.0- to 8. PH. My city water PH is around 7.5. When I feed , the water is around 5.9.

Pro mix Hp is a good potting mix.

I had the same problem. I started mixing my own potting mix of pumice and peat moss (50/50) and using compost as a mulch on top, not mixed in. I supplement the compost as I see fit (kelp meal, fish meal, bone meal, etc.) Then I top mulch with pine needle, wood chips, etc. I don't have problems with compaction or root rot. I grow plumerias and crown of thorns in pots this way. Perlite works just as well and it's lighter weight. This year I am trying a 3-1 ratio of pumice/peat moss and also try a similar ratio with pumice/coir. I will see how the coir works out and eventually switch to coir if successful just to be more environmentally conscious. Also, coir is supposed to be neutral. I just started to grow tomatoes and other vegetables in containers this year. I am starting late, but better late than never.

I'm also interested in this topic as EVERYTHING I'm planting this year is in containers. I've been using the Kellogg Pink bag (Raised Bed and Potting) mix as well and actually prefer it over the G&B Organics potting mix (both produced by Kellogg by the by).

I have many starts that are ready to be put into their pots and was about to ask the very question asked above. Living in Los Angeles, I'm somewhat limited to what's available in local hardware stores/nurseries.

I was going to make my own mix of the Kellogg / G&B raised bed mix (economical @ 3cu yard for $11), compost, and perlite. I also want to add something (mulch?) to the top of the containers to keep the soil from drying out (zone 10 here).

Questions: Anything wrong with the above? Any recommended ratios for vegetables and flowers? Can pinewood chips be used as top mulch? We have a MASSIVE bag left over from padding our nesting boxes.

Thanks!

Kyle, for annuals/seasonal plants like vegetables, what you are using is fine. By the time your potting soil starts to decompose and rot and cause harm to your plants, you have harvested your vegetables.

Mixing with perlite is a great idea to improve drainage and help with compaction. Home Depot sells a 2 CU bag for $16.97. If you have a cheaper source, please let me know. Throw some rocks/stones/pebbles at the bottom of your container. Your plant roots will extract minerals from them. Personally, I would use compost as a mulch and then use your pinewood chips as a top mulch to help retain moisture and in our So Cal heat, our container plants need all the help they can get to conserve moisture. Wood chips tend to steal nitrogen from your plants because that is what it needs to decompose and unlike living plants, it cannot take nitrogen from the air. I would supplement your compost with a high nitrogen source like alfalfa meal or fish meal to make sure there is plenty of nitrogen for everyone. Also, I agree that Kellogg Raised Bed and Potting mix is better than the G&B mix for your vegetable plants because the G&B mix has rice hulls and rice hulls do have arsenic. I don't know how much vegetables will take in arsenic, but I am conservative. If you have some already, use it for your flowers and non-edible plants.

Now if you were growing plants that are not annuals, then you would need a different potting mix. As I mentioned before, I grow plumerias and crown of thorns all in containers. I have 18 varieties of plumerias in 20 containers and 19 varieties of Crown of thorns. I would never put them in any potting mix that has recycled forest products as the first ingredient. That just continues to decompose and rot the roots. Root rot is not from overwatering, it's from rotting/decomposing pottings soil. I've learned that the hard way. That's why I mix my own potting mix. Compost and other organic matter belongs on top, just like what happens in nature. Leaves decompose on top of the forest floor. Peat moss decomposes very slowly, that's why I use it.

This year I am growing some vegetables and lots of tomatoes. I was slow to start on the tomato seeds and not ready to transplant to large containers (except for the ones I bought at the local nursery). I still want to experiment with the coir/pumice/perlite mix and will do that with my vegetable plants. I may even try some plants in just pumice and pebbles, (but lots of mulch on top, of course.) Will update at the end of summer!

FYI, you can get pumice from local topsoil companies that sell by the truckloads to landscapers. Just call and ask if they sell bagged products. I get about 35 lb bags of pumice for $7 each that way.

Hope that helps! Happy planting!
Yvonne

RBmom said:Kyle, for annuals/seasonal plants like vegetables, what you are using is fine. By the time your potting soil starts to decompose and rot and cause harm to your plants, you have harvested your vegetables.

Mixing with perlite is a great idea to improve drainage and help with compaction. Home Depot sells a 2 CU bag for $16.97. If you have a cheaper source, please let me know. Throw some rocks/stones/pebbles at the bottom of your container. Your plant roots will extract minerals from them. Personally, I would use compost as a mulch and then use your pinewood chips as a top mulch to help retain moisture and in our So Cal heat, our container plants need all the help they can get to conserve moisture. Wood chips tend to steal nitrogen from your plants because that is what it needs to decompose and unlike living plants, it cannot take nitrogen from the air. I would supplement your compost with a high nitrogen source like alfalfa meal or fish meal to make sure there is plenty of nitrogen for everyone. Also, I agree that Kellogg Raised Bed and Potting mix is better than the G&B mix for your vegetable plants because the G&B mix has rice hulls and rice hulls do have arsenic. I don't know how much vegetables will take in arsenic, but I am conservative. If you have some already, use it for your flowers and non-edible plants.

Now if you were growing plants that are not annuals, then you would need a different potting mix. As I mentioned before, I grow plumerias and crown of thorns all in containers. I have 18 varieties of plumerias in 20 containers and 19 varieties of Crown of thorns. I would never put them in any potting mix that has recycled forest products as the first ingredient. That just continues to decompose and rot the roots. Root rot is not from overwatering, it's from rotting/decomposing pottings soil. I've learned that the hard way. That's why I mix my own potting mix. Compost and other organic matter belongs on top, just like what happens in nature. Leaves decompose on top of the forest floor. Peat moss decomposes very slowly, that's why I use it.

Hope that helps! Happy planting!
Yvonne

Thank you for your knowledge, Yvonne!

I ended up purchasing two more bags (2 cu ft) of the Kellogg Raised Bed Mix as well as some Down To Earth 4-4-4 fertilizer. Anawalt was out of compost, hence the fertilizer purchase. We compost all of our food scraps into the chicken coop, but, I'm not sure I want to use that compost on container veg mid-season. So many of my seeds successfully started this year that I have room to experiment without fear of losing too much of my "crop". I'll be giving the pine shavings a go as top mulch.

And thank you for chiming in regarding perennials in containers. We have a plumeria that was gifted to us in a container. The person who gifted it to us is a retired landscape designer and it appears that he filled the container with his own mix as there aren't many woody-pieces that I can see. That said, I feel that the plumeria will need to be repotted this year or next so your soil recommendations will go heeded.

-Kyle

I make ALL of my own media and have been helping others online to overcome problems related to excess water retention. You can search online to see how much of an impact it's made on the container gardening community by doing a google search using Al 5-1-1 mix as the searchwords.

I actually started talking about 2 different mixes in 2004. One is what others eventually named the 5-1-1 mix and the other is 'the gritty mix'. If you did the search, I hope it makes you want to extend me at least some credibility, if not, I'll try to earn it because I do enjoy helping.

Most commercially prepared media are too water-retentive and inherently limiting because of that property, i.e. if you're the gardener who wants to offer plants the best opportunity to realize as much of their genetic potential as possible. BTW - I don't sell anything and all I push is a concept. Water retention is primarily driven by particle size, and the finer the particles, the greater the water-retention. In order to reap the rewards offered by fast-draining and highly aerated media, you'll need to start with a large fraction of coarse material. The 5:1:1 mix uses pine bark as the base.

By volume
5 parts pine bark screened dust to 3/8" (1/2" is ok if you can't find a 3/8" screen)
1 part sphagnum peat
1 part coarse or medium perlite
an appropriate measure of dolomitic (garden) lime, volume depending on batch size
Best if the mix sits moist for 2 weeks so the lime completes the reaction phase if you're planting anything susceptible to BER

That's it. The recipe is a starting point, and you can adjust the water retention by adjusting the amount of peat added.

I can tell you all the scientific stuff about water's adhesive and cohesive properties that work in concert as capillarity, the force of which can be greater than gravity and can cause a table of water to perch in the soil above the container bottom or above a drainage layer if you want the particulars. If there's interest, I'll start a new thread.

It's important to know, when you're looking for drainage and aeration, you must control the volume of fine particles. There is a threshold proportion of fine:coarse material you should understand. If you have a quart jar 1/4 full of sand, and you want to increase air porosity, how much porosity will a handfull of BBs add. You can see in your mind's eye that the jar with BBs has wonderful air pores between the BBs, so adding them to the sand should increase air porosity, right? In reality, it increases the volume of the medium but the actual volume of air porosity is unchanged. Therefore, o/a air porosity DECREASES, and, it continues to decrease until you reach the threshold proportion where there is exactly enough sand to fill all the spaces between the BBs. From that point forward, as you add more BBs the o/a air porosity increases dramatically. This is why you need a large fraction of coarse ingredients if you want the most from the soil.

You'll need to water more often, but your plants will love it. You might choose to go for the convenience of longer watering intervals, but the longer the watering intervals, the longer that saturated layer of soil at the bottom of the pot hangs around limiting root function and sapping potential. There's no judgment to be made about which way someone chooses to go, but at least you'll understand there is a penalty to be paid for media that offer extended watering intervals.

5:1:1 mix with objects for size perspective


Gritty mix - I have over 200 plants in this, and it's the most productive medium I've been able to come up with after 30 years of tinkering.

Al

Hello Al,
Can you please give your gritty mix recipe? I am very interested.

Thank you , Yvonne