30cm is almost 12" deep and will be more than enough depth. My preference for crops like this is to use long, narrow and fairly shallow containers such as the 'troughs' you see in stores. A common size would be 6" (15cm) deep and wide and the length varies, but I would get the longest one you considered practical for the number of plants you want in it. If you are sure the kind of container I am talking about think of a window box or deck railing box. Similar shape, but these don't mount to anything, you just set them on the surface.

justaguy2

Are you speaking about the right container for green peas or in general. I need advice on the container for green peas only. But, you see, may be some year I will plant strawberries in the same container. That's why I think my container should be both good for green peas and strawberries.

Yes, for peas.

It would also work for strawberries. Neither requires much depth for roots nor much total area.

Dear justaguy2

It seems to me you are the one who is able to answer my following questions.Be so kind to answer a couple of them on green peas growing. (to say the truth on the balcony not in the garden)
First question: At what temperature can I grow green peas seedlings in March or April outside the house not inside. Will any temperature suit this plant? Should I keep seedlings in a warmer place?
2) I got to know that it is possible to harvest green peas several times with 2 weeks interval. Only I don't understand should I plant new seeds into the same place where the previous vines grow into the the same holes or I should plant the new seeds in the completely new soil?
3)I got to know that peas don't like replanting, that's why they should be planted directly into the soil for complete growing period? Is it so?
4)Have some information about the fertilisers but don't know which and how much should I fertilise. Could you give the number and time of fertilising as well as the names?
That's all for now.
Hope to get the proper answers.
Thank you beforehand.

What kind of peas will you grow, specifically? I don't know what 'green peas' refers to. Specifically are you growing peas that like warm weather or a variety that prefers cool conditions like sugar snap/snow peas? For now I will assume you are growing a cool season pea and respond accordingly.

Peas like it cool, but germinate faster in warm soil. In your case this is easy to accomplish by sowing seeds in the container indoors and moving the container outside as they germinate.

You second question I am not certain what you are asking. Are you asking about succession planting? If so I would use 1 container for one crop and then use a seperate container to start another batch. However, for peas I wouldn't succession plant because once they start producing they produce until weather is no longer favorable and they shutdown and often die. At this point a second batch would likely fail due to weather. With cool season peas I do one crop in spring and a second batch I start late summer for fall harvest.

Peas can be transplanted without any problem as long as it is done while they are still young. As a means of dealing with slow germination in cold soils when I grow peas in raised beds I start them inside and transplant. No problems at all, but I always transplant before the plants are over 4-6" tall.

For fertilizer I would prefer a liquid fertilizer (or a powder that mixes with water before use). A good choice would be a 1-1-1 ratio such as 20-20-20 and many brands can be found such as Miracle Grow and others. There are other products on the market, but the Miracle Grow type are easy to find most anywhere and work well. If you are not using a commercially prepared planting mix then you should also add dolomitic lime to the planting mix at the rate of 1/4 cup lime per cu ft (1/2TBS / gal volume). This is to add calcium and magnesium which is normally added to commercially prepared mixes. This type of fertilization will work well for most anything in a container.

snow peas in earth box they are 15x30 and maybe 9 deep of soil.left side of the picture are the peas. they were 8 feet tall until a hail storm cut them down to 6. peas have pretty small root structure and there is 16 plants in that container. {{gwi:13111}}

Thanks but having some more questions:
1) please give the average number of seeds that can be sown into the container with 20 cm depth, 25 cm width and 70 cm length. I know that it depends on the kind of peas. Let's take snap peas for an example.
2)if I use newly bought planting mix one year, what shall I do with this mix next year? May I plant new peas next year into the same planting mix?
3) if I use one half of the earth from the former garden site + planting mix, should I still fertilise this mixture or let it be as it is. In order to kill any infections I can freeze this mixture or heat it in an oven. What could you say about it?
4) can I buy any tall sticks or trellis specially for peas supporting, taking into account the maximum height of this plant? Or should I tailor something for this purpose myself?
Thanks

And one more question about mulching. What kind of mulching the peas is the best one and when to start and to finish this mulching?

I would suggest spacing the plants 10-15cm apart (4-6").

You can reuse the planting mix for as long as it is able to grow vigorous, healthy plants. Please see Tapla's post for more info.

Regardless of what your planting mix is made of you will get best result in a container using a fertilizer. MG general purpose is fine and easy to find. Peas don't generally need a lot of fertilizer to do well so maybe a 1/4-1/2 strength dose every 2-4 weeks and see how it goes.

Peas generally don't require a lot of support, but the taller they get the sturdier it must be to deal with wind. I just use ordinary twine tied to posts and replace the twine with each crop. You could get fancier if you wanted to.

I generally don't use mulches in containers, but you can if you like. Anything non toxic would be fine. Wood chips, chopped leaves, moss, pebbles etc.

I have read a book on container gardening and now I am having the following 4 questions:
1)The book says that in container gardening we should use not soil but compost. Do you agree with this idea? Should I fill my container with pure compost?
2) The book explains how to plant seedlings into compost. But I intend to sow seeds first, so will the seeds grow in the compost filling?
3)The book speaks about the drainage layer importance. It speaks also about the self-watering containers. Is this drainage layer necessary when using self-watering container in green peas growing?
4) The book is firm in stating that the containers for vegetable growing (and other plants as well)should be at least 20 cm deep. But our garden shops sell mainly 14 cm deep containers both orinary and self-watering. Does it mean that these containers are not suitable, should I search for deeper containers to act in accordance with the book statements?

I would ignore the advice in the book, it sounds very old school and doesn't reflect current horticultural knowledge.

I would not suggest using compost in a container although some do. In your case whether you are using 20 or 14 cm deep containers these would be considered shallow containers so I definitely would not advise any soil or compost, only a fast draining soil-less potting mix.

If you have read Tapla's post on water movement in containers in this forum you would be familiar with the concept of a perched water table. A layer in the container from which water won't drain. This perched water table is a bigger issue in shallow containers than in deep containers. If your pot is 14cm high and the perched water table is 6 cm high your plant's roots have only 8 cm of room to grow in that drains excess water. With the containers you will be using you don't want *any* perched water table.

The idea of a drainage layer in containers is a very good sign the author doesn't know what s/he is talking about. Drainage layers in containers do not work - period. If you find your soil-less mix is holding too much water then using a wick hung out the bottom of a drain hole will work to remove the PWT, but a drainage layer will not. All using a drainage layer will do is take up growing area and raise the height at which the PWT occurs. This is more thoroughly explained in Tapla's post I mentioned above.

To the extent you will be using self watering containers things like drainage layers and wicks don't apply as the design of the containers doesn't permit using them effectively. In such a case just fill the container with a decent soil-less potting mix and plant. No need to fuss at all, 'just do it' :)

Hi there,

I grew sugarsnap peas in the winter, in long troughs like you and justaguy are discussing - 15cm tall. I planted 7 seeds per trough, in 2 troughs.This produced enough sugarsnaps for daily grazing. The soil was pretty exhausted from tomatoes, but they did fine. The hardest part was staking them - while the depth was fine fo rthe plants, it's really too shallow for bamboo poles to stay upright in. Next time I would look to support them against a railing.

That book on container plants was written in 1995. It explains the value of compost with the nutrients being a part of this compost and keeping the plants nourished without first-time additional fertilising. Though it speaks about the necessaty of later additional fertilising, but not at once as it is a case with soil-less potting mix I guess.
1)When am I to start giving the addititional fertilising to the soil-less potting mix and how often should it be done when growing green peas?
2) The book speaks as well about the importance of potassium fertilising as it helps to get much better harvest contrary to nitrogen that brings better dense foliage. Has this fact changed since 1995?

Thanks.

Loori - Actually, finished compost adds VERY little in the way of nutrients. Its value lies mainly in improving the structure of mineral (garden) soils, but structurally speaking, it can present problems quickly in containers due to rapid, even immediate soil collapse and the accompanying excessive water retention.

Peas need little N supplementation in the ground, but they will need SOME in containers. I think you would do well to mix a Tbsp of potash (for the K - potassium) per gallon of soil before planting and fertilize regularly with weak doses of any 1:1:1 ratio fertilizer like MG 20-20-20. You can start the fertilizer regimen as soon as the plants are situated in their new container.

Al

As far as I understand the three numbers like 1:1:1 or 20-20-20 denote for the first number-nitrogen. But what elements do the second and the third numbers denote? And what units of measurement do they denote?

1:1:1 is the ratio, and 20-20-20 is the % of NPK by weight. The first number denotes 20% nitrogen, the second 20% phosphorous, the third 20% potassium. 1:1:1 RATIO fertilizers will be things like 20-20-20, 10-10-10, 12-12-12, you get the idea. It just happens that 20-20-20 Miracle-Gro (or one of the other popular makers) is soluble (important) and readily available.

For most plants, a fertilizer with a 3:1:2 ratio is a better choice. It supplies nutrients in the approximate % that plants actually use them. Legumes (peas) are a little different. They need little nitrogen because they form a relationship with microorganisms that convert atmospheric nitrogen to ammonia, and the plant then absorbs the ammonia as a nitrogen source.

Getting back to the 3:1:2 RATIO fertilizers: Miracle-Gro 24-8-16 granular soluble (24% N, 8% P, 16% K) and 12-4-8 liquid, as well as Foliage-Pro 9-3-6 are all examples of 3:1:2 ratio fertilizers.

Got all that? ;o)

For more info, the thread on Fertilizer Program for Containerized Plants might be helpful.

Take care, Loori.

Al

To further explain: Since 9-3-6, 24-8-16, and 12-4-8 are all the same RATIO (3:1:2), in the end, they will all furnish approximately the same amounts of NPK. The reason is, the manufacturer knows how much fertilizer it takes to reach a certain level of electrical conductivity in the fertilizer solution. Since that is a target, they would direct you to use twice as much 12-4-8 as 24-8-16 to wind up at the same strength solution.

Another way of saying it is: Imagine you have two granular fertilizers to compare. They are both in 1 lb boxes and are the same price. One fertilizer is the 24-8-16, but the other is labeled 6-2-4. The 24-8-16 is a much better value because it will supply 4X as much NPK as the 6-2-4. 20-20-20 at the same price as 10-10-10 provides twice the value because it contains twice as much NPK as the 10-10-10.

When we talk about fertilizers here, we should be using a colon between the numbers when we are talking about ratios (1:1:1, 3:1:2) and a hyphen between the numbers when talking about % (20-20-20, 24-8-16). I hope that helped a little more.

Al

I am reading your answers attentively right now. Thanks a lot.
Now thinking about buying right depth container, though the choice is very limited. I have seen only 14 cm deep plastic containers, self-watering plastic containers also 14 cm deep and one deeper plastic container that is 18-20 cm deep but all these containers are rather narrow. There are no broad containers at all so far. What kind of container would you advise for green peas growing? Shall I take self-watering plastic container? Only afraid that the depth will not keep the suuporting poles upright.

Container depth becomes more critical as soil water retention increases. The heavier and more water-retentive the soil, the deeper the container should be.

Can you use a large round container & insert a tomato cage into it? You could use lattice tied to the upright wires on the cage & then wrap twine on the lattice (or use your imagination & select more attractive materials if appearance is important) to extend the height. The cages could be secured to both the container and something structural to offer additional support if you feel there is danger of toppling.

Do you have 20 L buckets there that could be pressed into service (if you can't find the long, narrow, rectangular ones JaG mentioned)?

Al

Thanks a lot for your answers on fertilisers ratio, as if now everything is clear.
1)As for the right container you advised a round one. Not sure that there are such on sale, but i can buy bathroom washbowl and make holes in its bottom. Only it will be problematic to find a kind of big saucer for draining water storage. How to solve this problem?
2)What about bamboo poles, can I insert them at the sides of the bowl and make a kind of igloo out of them? Will the peas tendril be able to climb up such poles?
3)As well you didn't express any attitude towards self-watering containers.What can you say about them?
Thanks.

As for my above asked questions now I would need only the answer on the 3rd question, plus I have two more addtitional questions if you don't mind.

1)As if draining layer is not necessary in the container growing because it causes water retention or something like that. So Ive'made up my mind not to use this layer, but the problem arises -how to keep the potting mix from washing out through the holes? Shall I use any cloth to cover the holes?
2) How many liters of potting mix will go into the container with the dimensions: 75 cm-length, 31 cm -height, 29 cm- -width.(I can reduce the dimensions of this container by using less space of it, namely leaving out 8 cm border from the top, then the dimensions will be like:length-72 cm, height-22cm, width-25cm)?

Be so kind to respond to my questions.

One more question: may I space my seeds in the container in rows at 5cm distance from one to another, as well leaving 5 cm between the seeds in the row? I just want to sow as many seeds as possible in one container and leaving 25 cm as it is written in some articles is stealing the valuable space in the container to my mind.What can you say on this?

Loori, I am learning with you as JaG and Al answer many of your questions, and I appreciate their generosity as much as you do.

One thing that might make it a bit easier for those of us who are used to using inches instead of cm, would be for you to use this link and convert to inches before asking. I could be wrong but I believe both Al and JaG may be doing that to answer your questions.

Here is a link that might be useful: Online Conversion

I think 5cm spacing is probably going to be a little on the over crowded side, but it might work out OK. I would suggest more along the lines of 4-6" spacing (10-15cm) as a starting point.

Answers to Loori's questions 4 posts above:

1) I use fiber glass window screen to cover the drain holes (very inexpensive) in most pots, and 9 x 12 sheets of perforated plastic meant for needle crafts (from a hobby shop) - cut to needed size.

2) There are 67.5 liters of soil in your container if you fill it. If you use the second set of dimensions, it will require 39.5 liters.

Al

I appreciate so much your valuable responses, which nevertheless call forth new queries:
1)how thick should the cloth used instead of the draining layer be?
2) Does net using provide a good protection from the birds?

Thanks a lot.

Thickness isn't important. If you haven't already please read Tapla's post on Water movement and retention in this forum. Among many other valuable things you will learn about using wicks for drainage if they become necessary. With a fast draining potting mix they aren't usually necessary though. They are usually used to compensate after the fact.

I couldn't tell you about bird nets as I have never used them. Some people have a lot of problems with birds stealing their produce, but I never have fortunately.

I've reread Tapla's post on Water movement and retention in this forum, namely only her initial article without comments.
1)Do I understand correctly that ordinary small cell netting is quite good for drain-holes covering? Won't it be rotting?
2)As for wicks, may I use a piece of ordinary medicine bandage?

1) anything that doesn't rot & will let water pass (like insect screening, fine hardware cloth, onion bags, etc) will serve the purpose just fine. It's not a critical issue at all.

Try to stay away from cotton gauze or other cotton products that quickly break down. Shoe laces that absorb water work well, man made chamois, ... anything that you can visibly check and see that it is working. The more durable - the better.

Al

What about the scientific base for your statements on the existance of perched water table? Who discovered it and how many people support this discovery?

"Why are ye doubtful, oh ye of little faith"? ;o)

Al

I trust your advice, only it is interesting to get to know the sources of your beliefs on this question (perched water table etc.). Are these trial suggestions or scientifically proved methods?

The source of my beliefs is research, practical experience, and observation. The application is borrowed from the science of geology, but physical laws of adhesion, cohesion, and gravity combine in container soils to govern its variable effect. The primary influence is the particulate size of container soils. You can prove its (PWT) existence in myriad ways. Hold a saturated sponge with its largest (in area) surface horizontal until it stops draining. Turn the sponge so it's smallest surface is horizontal, and more perched water will drain as the height of the PWT equalizes in a lesser volume of sponge. Grasping the sponge by a corner after it has again stopped draining, so one corner is down, further reduces the volume of sponge occupied by perched water and even more water will drain. Finally, with a corner down and no draining occurring, touch the corner with a toothpick held vertically (a wick) and even more water will drain.

Or: Hold a toothpick to the drain hole of a container of saturated soil that has just stopped draining & watch its wicking effect drain more water that had obviously perched in the container.

If you care for more details of how it all works, follow the link provided.

Al

Here is a link that might be useful: More information

Thank you for your thorough explanations. Now I have no doubts concerning the sources of your beliefs and I will definetely take them into account when planting in the container.

Loori, you seem to be a skeptic who requires evidence. GOOD FOR YOU! As long as the teacher isn't full of BS (and Al/Tapla isn't) skeptics not only make the best students, they often go on to teach others as well since they have confidence in what they have learned.

This is a part of something I left on another forum last Fri: "I think it's a good thing to entertain our opinions with some measure of doubt. I wouldn't want anyone to believe anything dogmatically, not even my own assertions ..."

Al

As I understand you are not amateurs but real professionals in this field. I mean you have special education not just neighbours advice?

Lol - what constitutes "special education"? If we were professionals in this field, you might expect to have your Visa at the ready. ;o) Maybe it's a cultural thing, but while it's good to doubt, and it is always a trait that serves the wise well, there must be a basis for it if it will be perceived as rational. I've answered several of your questions, so now I'll pose one to you. What is the basis for your doubt?

I'll spend a considerable amount of effort to help those in want of answers when I feel I have something enlightening to offer to an open mind, but I kind of draw the line when asked if I have the credentials to offer free guidance. You'll need to decide the worth of what I offered, and whether or not my offerings have roots in known science, on your own.

Take care - good luck.

Al

I know that there are some horticultural vocational schools where the horticultural professionals teach students. So I just made an assumption that you could be one of them. If not I still trust your advice because you have experience in this field. That is the explanation of my questions.

Here's alink to an article about getting started with container gardening. It may be useful for anyone intrigued by this thread enough to think about getting started with potted plants.

Here is a link that might be useful: Container Gardening

May I use newspaper to cover the drainage holes in the container instead of any kinds of net?