Why don't the manufacturers of these devices make them out of a clearer or translucent plastic like a milk jug?

For a very good reason. :) Unlike top growth, roots are negative-phototropic. They don't like or tolerate the light exposure or the heat that can result.

Dave

Yeaaah, I understand that, but...

Lots of folks "pot up" to those throwaway plastic cups that are translucent. I've done this a bit myself with no loss of plant life. I agree that keeping them in clear pots of any sort for a long time would result in some root death, but the only point I was making was having the ability to see when roots are getting out of hand is a clear signal to pot up or get them in the ground.

I used cardboard egg cartons last year with pretty decent success. They are quite shallow, so I make sure my seed starting mix is filled to the brim, damp, and compact before adding my seeds, but it has a huge advantage... the roots tend to push out of the bottom of the cardboard when they get long enough. I just lift them up and check the bottom. I also love the fact that all I have to do to tell when they are dry is to feel the egg carton. As a novice at this, I can't say I'm a good resource, but I had lots of survivors last year. Good luck!

Most trays have drainage holes on the bottom. When you see roots there it is time to pot up.

Dave is also right, if roots wanted to see light they would be above ground!!!

SCG

I have been using clear plastic cups to pot my seedlings up for the past 4-5 years and it never occurred to me that it might be a problem for the roots. Pretty much everything I grow, both veg and flower eventually move into 9oz clear cups. With the cups jammed together in the tray I don't suppose much light gets to the roots - except for the ones on the edge of the trays, and even those are sitting in cell packs, so only the top half or so is exposed.

I will keep an eye on them this season and see if the plants at the edges of the tray seem weaker due to roots getting light - but I have certainly never noticed it in the past.

I agree with Mandolis. I especially like the translucent mini pots for cuttings--you can see root formation at a glance--but have also used them for starting seeds without any problems; not much light hits the roots.

JME,
Gary

It is your choice of course but there have been plenty of published studies done on the effects of light exposure on roots. The root axons are damaged and burned. That interferes with the O2/CO2 exchange as well as the uptake of nutrients.

The damage done to the roots and subsequently to the plant may not be visible to the human eye but that doesn't mean it doesn't exist. Microscopic examination clearly shows it.

Since there are numerous alternatives available for containers and there are numerous signs one can use for the need to transplant, why choose to intentionally do something proven to be detrimental to the plant?

Dave

I have been spending way too much on annuals for the 20 to 30 containers I plant outdoors for the spring-summer-fall. My urban lawn soil is terrible, shady, and infested with Maple tree roots, so I do most all my gardening in containers. I don't have a lot of room indoors, so I was intrigued by the Park "Bio Dome" and growing from seed in general. I am new to this forum but would love to hear comments on the subject.

This post was edited by neuf on Wed, Mar 12, 14 at 9:42

neuf -since you are starting a new topic with a new question it would be best to begin a new thread. People tend to keep their eye on the new stuff coming in rather than looking back at older threads. However ....

The 'biodome' looks just like any other seed tray with a plastic lid, as far as I can see, plus sponges which are pointless. It would be cheaper and easier to invest in some simple trays, square modules (pots) and some seed starting mix. This contraption claims to prevent spindly seedlings which is nonsense. It is the correct amount of light which will do that, not a plastic dome.

Agree with what floral said above. There have been several previous discussions here about them - most negative. I linked one below and the search will pull up others if interested. If you have more questions about them please start a new discussion.

Save your money. Annuals are easy to grow with a simple and inexpensive set-up.

Dave

Here is a link that might be useful: Park's Biodome discussion