Plant production: container options

1. Plant production: container options David A. Bainbridge Alliant International University Author: A Guide for Desert and Dryland Restoration 2007

2. Why containers • Container planting is desirable because direct seeding may succeed only once every ten years in the desert (Cox et al., 1982) • Good seedling survival and growth from containers can be expected even in areas with less than 3 inches [75 mm] of rain per year if plants are well prepared • And provided with protection from grazing and minimal water

3. Deep containers • The choice of container type is guided by ecological, physical and bureaucratic issues • Use local site adapted seed • Deeper (taller) containers have often been more successful • The more uncertain the climate and the bureaucratic environment - the bigger the containers should be

4. Container goals • A container that will produce an acceptable seedling at the highest practical growing density, in the shortest time, at the lowest cost • Easy to handle and plant • Suited to the project, site environment, and planting and maintenance program

5. Restoration v/s landscape plants

6. Root development wanted • Small shoots and vigorous roots are wanted • The root/shoot ratio should favor roots • Fertilizer management and pruning may be used to get good root/shoot ratios

7. Container options

8. Supercells • The ten cubic inch plastic cell fits in a rack • The plastic holders are relatively fragile • I like to transfer cells to 5 gallon plastic bucket with a rack

9. Plant bands • Plant bands are square tubes made with folded and glued plastic or foil coated cardstock • Plant Bands with holes can lead to root tangles • Plant bands can be pulled up over the plant in some cases for minimal root disturbance

10. Half high Smoothwall PVC 6” x 16” If drainpipe or less shiny plastic is used it can be hard to get the plants out without disturbing roots • The bottom can be closed with a crossed wire and wire mesh disk or shadecloth or screen taped onto the pipe • This summer I am trying Tubex shrub plant protectors as containers. Pulling it up after planting would give a secure and effective protector

11. Container suppliers • Listed in book - one good source is Stuewe and Sons • Plant bands can be custom made at any size

12. Other options • Citrus pots and tall containers • It is often good to use tapered pots upside down - this minimizes root disturbance on planting

13. Tall pots • The Center for Arid Lands Restoration at Joshua Tree National Monument (JTN Park) pioneered the development of the Tall Pot made with 32 inch tall, 6 inch diameter PVC pipe (Apache 2729)

14. Jelly Roll • For some situations and species the best container is no container • Plants are grown in a loose soil mix, then rolled bareroot in a roll of absorbent paper or Kimtex • A cooler can hold hundreds of plants

15. Other challenges • Timing - what do you do if contracts are delayed? • This field of cholla was finally plowed down - it became too hard to handle after a long delay

16. Soil Mix • Many desert species have limited defenses against root rots, damping off, and other pathogens • They may also have high oxygen demand • Well drained soil mix (washed plaster sand is often used) • Experimental trials recommended before big grow-outs are attempted • The soil mix must fit the container, plant species, irrigation, and nursery operation

17. Inoculation • VA mycorrhizal fungi (P) and rhizobia (N) may be important for some larger disturbances such as mines and borrow pits • But on most sites native species will colonize roots • If needed collect inoculum on site and put in planting holes

18. Handling • Efficient and gentle handing and staging is important to reduce the cost of planting and improve survival • Contract growing may be more efficient than starting a local “nursery” which can be labor intensive and 24/7

19. Cost per survivor • It depends on the year, the site, the planter and the species • With water and plant protection • An average survival and cost per survivor might be something like • Supercell 40% $15 • Plant band 60% $10 • Tall pot 95% $30

20. The right choice • There is no one container or production system suitable for all conditions and species • Deep containers generally result in higher survival and better growth • A combination of small through large containers is often best • This might include 10% tall pots, 20% half highs, 30% plant bands and 40% supercells

21. Out of season • Growing plants out of season never seems to be worth it • Even when contracts come at the wrong time it is better to wait • Build in sufficient time to collect seed, prepare sites and grow healthy plants

22. Everything has to be right! • Neglect of any of the key factors may lead to complete failure or very low survival • Plant protection rarely receives sufficient attention • Irrigation is important and rainwater harvesting can help • With careful preparation, good protection and some water -- excellent survival and growth may be achieved with minimal water use, limited maintenance, and low cost

23. The toughest conditions • Off road vehicle damage A-BDSP • Far from the road, 4wd access only • Pitting, seeding and container planting • Low budget - or the road could have been filled in