Unity College Dartmouth Greenhouse Week 4

Week 4: 11/14/16-11/18/16; ~43 hours left

Sorry I have been busy with thanks giving preps, so this blog post is late!

At the greenhouse we have multiple substrate and soil type based on the requirements of the plants, the substrates are usually used for the orchids and other epiphytes.  We have 3 major soil mix types: Metro Mix (for the general unspecific plants); Cactus Mix (for the xerophytes and plants that require high drainage); Tropical Mix (for the plants that are in the Tropical Room).

This week I got to learn how to mix up a new batch of the cactus mix soil, which I was very excited about. Since being put in charge of the Xeric Room (ie Cactus Room), I have done a lot of re-potting and dividing and so the cactus mix had become very depleted.  Each soil mix has their own particular recipe specific to the plants that are to be potted. Cacti need soil that is well drained and some what alkaline ('basic', ie acids and bases).

The bin that the cactus soil mix is held in.

To measure out the larger amounts of ingredients we usually use metal basins that each about half a bushel.  I first measured out "garden variety" potting soil mix (I made a pun there) as the base for the mix.  Then I added a decent amount of sand (I don't think that it matters what type of sand, just the size of the particles). The sand adds drainage to the soil and matches the natural soil type that cacti grow in.

The next two ingredients are used to help with the drainage allowing the roots to dry out
Perlite is a volcanic rock that is very similar to pumice but is a brilliant white. It is very chalky and dusty.  Turface is a gritty gravel like mineral that has a reddish coloration. According to my boss it has been used in athletic fields for drainage and traction (ie the reddish-brown areas of a baseball field).  I had to ware a face mask while handling the perilite and turface due to the dust they created.  By themselves the aren't particularly toxic or caustic, it is the actual inhalation of the dust they create that is harmful.  As a final additive we add a small amount of the pellet fertilizer, 10-10-10 and Calcium Carbonate (CaCO3) because cacti usually like the soil to be a little more alkaline.

Perlite (left) and Turface (right) I was unable to take pictures of the process itself as the dust would damage the camera.

When mixing up the soil I would use a metal dust pan to fold the layers together on the prep table in the prep room.  After mixing, I was able to re-pot some of the plant
It is very satisfying being able to not only re-pot plants your self but mix up your own soil as well.

This Wednesday was the last Botanical Illustration Class that was to be held during my stay as an Intern.  I had not known this earlier but Dartmouth College worked on a Trimester Schedule not a Semester schedule. The students classes ended this week and they would restart after New Years.  This also effects the other community events that the College offers during the semester.  I am somewhat familiar with the trimester method as my older brother got his bachelors degree at a college that had a similar set up.

During the class we mainly did a wrap up of what we had learned previously and the teaching artist's work.  Many of them were on local Vermont spring ephemerals such as ladyslipper orchids and crocuses.  We went on to discuss in detail the botany of the native ladyslippers.  One in particular I had not known about or realized was so local was the Yellow Ladyslipper or Cypripedium parviflorum (it was originally included with the species C. calceolus, which is a European species).  The specific epithet "calceolus" means "calcium rich" and refers to the fact that the orchid only grows in alkaline soils.  Local orchids are unique in their germination methods.  Unlike other seeds, orchid seeds have no extra nutrition added (ie no endosperm or pericarp). To germinate those seeds, mycorrhizal fungi are require to be present in soil.  This mutualistic relationship allows the orchid to gain enough nutrients from the fungi to grow.





We also were reminded to practice regularly even though there will be no more class.  That is the only way we will improve.  Everyone in the class was very kind and helpful allowing me to take part even though I am not an OSHER member or signed up for the class.  I hope to see them in the future outside of the class.


As with any greenhouse, we have to keep control of the growth of the plants so they do not strangle the other plants or the greenhouse itself.  Many of the plants in the different rooms ended up strangling and choking the equipment and pipes.  Since it got to the point where the climate controls for the rooms were getting effected, I was tasked to clip back those vines and plants so that they don't choke the greenhouse.  I worked mainly in the entry room, main hallway, tropical room and cacti room.  It was very difficult work as I had to use a ladder and many of the vines had gotten seriously tangled within each other and the greenhouse infrastructure.  The wax plants were probably one of the worst to work with as not only did they have a thick waxy cuticle and milky stick sap that is almost impossible to get off.  I make a specific point that there were enjoyable parts of this work as I was able to view parts of those plants that otherwise were hidden.

A Bougainvillea vine blossom tangled up in one of the misting pipes. There were a good amount of thorns on this plant so it was very tricky to remove.

Two views of the Bower Vine (Pandorea jasminoides), the vine itself (left) and a flower (right). Many of the vines had escaped up into the sun screens to get more direct sunlight.

Have a great break!

Unity College Dartmouth Greenhouse Week 3

Week 3: 11/7/16-11/10/16; ~86 hours left

This past week  has been tough for me to function with my typical enthusiasm and focus due to the election and  resulting aftermath.  I feel as though protecting the environment that we have left has just got much harder.

To distract from politics I have been focusing on tending to the basic needs of the plants (ie fertilizing, pruning, repotting) and the general upkeep of the greenhouse itself (ie clean drains, sweeping or squeegeeing the floors).  During the week I would often survey the different rooms to look for tasks that needed doing. I focused specifically on the Subtropical Room and the Cacti Room to trim and dead head the ferns and other 'leggy' plants or repot the xerophytes that were overgrow.

Rabbit's Foot Fern (Davallia fejeensis) in the Sub-tropical Room, a large section of the subtropical plants are ferns and primitive plants (ie mosses, liverworts, clubmosses).

To keep track of the species we keep in the greenhouse we keep inventory lists. There are two separate lists one for the orchid and the general plant species. We have a large variety of orchids and most are housed separately.  The lists are organized by family and then species and includes their location, their potting information (ie size, re-potting dates, division dates, quantity).  Every time we re-pot or divide a plant we have to update their information in the inventory list. Normally this is done by hand on a printed copy that is then updated digitally.

The illustration class this past week was probably what helped me get through the day on Wednesday.  The lesson was to show the incremental steps involved with layering the watercolor to give the desired effect.  They also discussed the inclusion of fractals and Fibonacci's Sequence into botanical illustration and other precision based art forms.  They mentioned the NH artist, Maxfield Parrish as a prime example of precision and composition.  He apparently used surprisingly complex equations to create his art pieces whether they be murals or children's book illustrations.

A water lily called Blue Pigmy (Nymphaea colorata) that is native to eastern Africa. Its blooms only last one day so I was lucky to take pictures when I did!

A large percentage of the research done in the research section of the greenhouse is with transgenic rice.  Some of the professors are working on a way to prevent the ability of the rice to absorb heavy metals.  Accumulation of those metals lead to negative health effects.  To test the content of that rice, they have to harvest each generation of the rice seeds and pick the they want for the new generations.

In those experiments they must have a 'zero pest policy'. Any biological contaminations would potential change the outcomes.  The particular issue that the researchers had was with aphids attacking the young rice plants.  If the aphids are not removed completely they will prevent the rice seeds from forming.  This would halt the entire experiment as they need to be able to test those seeds.  To deal with this, we at the greenhouse use pesticides as a sterile environment must be maintained.


When using pesticides you are suppose to use multiple modes of action so as to not let the target species develop a resistance. Multiple modes of actions just refers to the different ways the chemicals are applied and/or effect the target.  One pesticide that was a possibility was Pyrethrum TR (aerosol spray).  It is derived from chrysanthemums.  For the chemical to work it must have physical contacted with the insect's cuticle.  I don't know the specifics but it effects the sodium channels in neurons, killing the insects.  Another pesticide with a different mode of action was Preclude. It is an insect growth regulator which means it prevents the insect from fully maturating to a sexually active adult.  This pesticide is not practical for dealing with aphids as it does not kill the young and aphids have a very flexible life cycle that allows them to reproduce at multiple stages.  The final type of pesticide we discussed was a systematic insecticide called Marathon II.  It is absorbed through the roots and transmitted throughout the plant.  When the insects feed on the plants it kills them.  The pesticides last for a couple weeks.

On Thursday, our order of bio-control species finally came in:

#1: Steinernema feltiae (Predatory Nematodes): These are the same nematodes that I used in the research lab to inoculate the mustard relative.  They requires lukewarm water to become active.

#2: Cryptolaemus montrouzieri ("Crypts"): They came as adult beetle. Hopefully they will mate and then lay their eggs on the plants with high populations of mealybugs.

#3&4: Predatory Mites- Neoseiulus californicus (left); Stratiolaelops scimitus (right): They will be let out on certain plants to consume the larval stages of the thrips and fungus gnat.

#5: Chrysopidae (Lacewing):  The eggs are attached to little paper sheets which will be hung on the plants.  The larvae which are voracious predators are supposed to hatch and then start consuming what ever pest species it can get its mandibles on.

#6: Eretmocerus spp. (Parasitic Wasp): This wasp could only be sent as a pupal stage rather then an egg as the larval stage is parasitic. They will parasitize aphids turning them into something like a mummy.  This lasts until the larva is ready to burrow out and begin metamorphosis, starting the process over again.

#7: Amblyseius cucumeris (Another Predatory Mite): I had to replace the old packets with the new ones on the plants in all the rooms except the Cold Orchid Room.  The temperature is to cold for them.  We can also compost the old bags without going through a complex process, which is nice.

Here are some pictures of the Welwichia (I know that some of you were asking for them). Unfortunately they do not show just how impressive the fronds are:

Have a great weekend!!

Unity College Dartmouth Greenhouse Week 2

Week 2, 10/31/16-11/3/16:

I feel as though I have gotten a stable daily schedule after the first week of working.  I usually start out with a preparatory task like sweeping the floors from leaves and dead plant matter or cleaning floor drains of the different rooms.  Typically this will last until ~11:00 or 12:00 when I take a quick lunch break.  After lunch I usually have a variety of more involved tasks like fertilizing the plants or working on pest management.

Since the Greenhouse has a high diversity of plants, we have to use multiple types of fertilizers to deal with each specific plant type and environment.  Most of the fertilizer that we use are diluted with water so as to deliver the fertilizer directly into the plants system, although we do have some pellet form that we use to supplement some of the plants.  I usually use gloves and boots when I am handling fertilizer as I suspect prolonged exposure to some of the chemical should be avoided.

Orchids, especially the ones living on moss require specific fertilizer that they and their substrate can tolerate.  We use a special fish and seaweed fertilizer that is diluted with RO (reversed osmosis) water to fertilize the wall orchids in the cold orchid room, since the typical orchid fertilizer would hurt the moss. To apply it we use a hand-held pump sprayer.

The orchid wall in the Cold Orchid Room (all of the orchids on this wall are epiphytes and are attached to a substrate which is in turn attached to the moss)

We used a different fertilizer called "Epiphyte's Delight" for the bromeliads (epiphytes and soil-bound) and carnivorous plants in the Tropical and Sick Orchid rooms (nursery for carnivorous plants).  It was initially in Granular form but was diluted using the RO water and a different hand pump sprayer.

Myself using the fertilizer for the bromeliad in the Tropical Room.  Taken by my co-worker Terry.

We do have other diluted fertilizers for more general plants.  One of them is applied use a mechanical dispenser called a Dosatron. It is very large and we have to physically hook it up to the water system. It will mechanically measure out the correct ratio of fertilizer to water without monitoring it regularly.  It is too strong to be used for the orchids or the epiphytes.

As Integrated pest management is a part of my internship I often am on pest removal detail.  The most common of these tasks is removing mealybugs and scale insects from the plants with Q-tips and alcohol.  Often I have to do this to plants that are overgrown or crowded together.  We do have species that prey on the mealybugs, the Cryptolaemus montrouzieri ('Crypts' for short) larvae.  They often have similar coloring and shape but are much larger.

A Cryptolaemus montrouzieri larva (center) and mealybugs on the same branch (below)

On Wednesday morning I was able to work hands on with some of the control species they use to prevent infestations; specifically beneficial nematodes (Steinernema feltiae).  They come in a dried suspended state and require water to move.  To make sure of their viability we always check under a microscope (the straight nematodes are dead). To make sure the nematodes are thoroughly dispersed I had to stir solution every 10 minutes.  They need to be apply to the soil. They are predators that eat the larvae of thrips and fungus gnats.  We used a ketchup dispenser to apply them.

The packets that the nematodes (Steinernema feltiae) came in.

Often we have to help the researchers of the plant laboratory to inoculate them with the predatory nematodes as the laboratories tend to water the plants too much making them a target for thrips and fungus gnats.  The plants they were using was a mustard relative as test subject because it has an extremely fast life cycle (~6 weeks) meaning they can have multiple generations in a short amount of time.  Each sections of plants were store in what they called Biochambers (kind of like high-tech sterile refrigerators except without the cold).

On Thursday I got put in charge of the Xeric Room or 'Cacti room'.  I was super excited about this. It is a bigger responsibility than it sounds on paper.  I will do my best to live up to it.

New World species' bench of the Xeric Room

The room itself is split down the middle with Old World species  on the left (mainly Africa) and the New World species on the right (mainly South and Central America).  They have a wide variety of succulents and xerophytes (plants adapted for dry environments). A lot of them are cacti and aloe.  An example of a xerophyte that is not a succulent was the Welwitschia. It is a very sensitive and bizarre plant, looking like cross between a pine cone and seaweed that has been dried bone hard.

Mammallaria hahniana "Old Lady Cactus" (that is the real common name; no joke!)

Until next time!

Unity College Dartmouth Greenhouse Week 1

I just started working at my Unity College Biology Internship with the Dartmouth Life Science Center Greenhouse on Monday the 24th.

Main hallway of the life sciences center greenhouse

Overall the internship has been going well.  My official title is Greenhouse Assistant and will be focusing on Exotic Horticulture and IPM (Integrated Pest Management).   I set up my work schedule so that I work Mon-Thurs at about 8-7hrs per day.

With the exception of my self there are only two other regular employees, my Site Supervisor Kim and senior coworker Terry.  Both of them are really nice and very supportive.  I am learning a lot about what goes into running a research greenhouse.  Greenhouses, especially ones that are as extensive as this one is are much more technically involved than I had initially expected.

My boss Kim (middle), co-worker Terry (right), and myself (left); (photo taken by Terry) 

I got a standard tour of the greenhouse including the rooms reserved for staff such as the sick rooms and the prep room. Each section of the greenhouse is arranged by climate conditions which are maintained via mechanized controllers:

• Tropical room
• Sub-Tropical  room
  
• Xeric room (i.e. succulents & cactus)

With the orchid rooms separated from the other plants (orchids being more susceptible to pathogens):

• Warm Orchid room
• Cool Orchid room

And two quarantine rooms used to separate the sick and infested plants:

• Sick plant room
• Sick orchid room

The room we mainly worked in when dealing with individual plants was the prep room. It was kind of set up like a cross between a gardeners tool shed and a veterinarian prep room.  We would use it when re-potting or removing pests like mealybugs (Pseudococcidae) by hand.  It is also where they store the soil mixes and fertilizers.

Prep room

There is a Community botanical illustration class on most Wednesday and I was able to take part in.  The artist was previously a scientific illustrator that found their way into
botanical illustration which is slightly different.  It was all very fascinating and informational. Although I have dabbled in some hyper realistic art style before, the class worked to achieve a level that was much higher than I had expected. 

Through my art apprenticeship I learned the benefits and loosing my style and going large, This is almost counter to what is traditionally involved in botanical illustration. It requires a large amount of technical skills and precision. The illustrations also rarely get larger than ~8.5”×11” so it was a bit of a readjustment.  The way the instructor described what a botanical illustrator is 90% technician and 10% artist.

I don't have enough space to describe all of what I learned over this first week.  I am enjoying learning the vast diversity of the plants and helpful control species.

Flowering orchid from the Warm Orchid Room (can't remember the exact taxonomy)