To solve this optimization problem, we first need to translate the given natural language description into a symbolic representation. This involves defining variables, an objective function, and constraints in terms of these variables.

Let's denote:
- $x_1$ as the number of coleus,
- $x_2$ as the number of roses.

The objective function described is to minimize $2x_1 + 9x_2$.

The constraints given are:
1. The total combined growth speed from coleus and roses should be at least 43: $0.82x_1 + 1.29x_2 \geq 43$.
2. The constraint mentioned again for emphasis but it's the same as the first one, so we consider it only once.
3. Minus eight times the number of coleus, plus 8 times the number of roses should be no less than zero: $-8x_1 + 8x_2 \geq 0$.
4. The total combined growth speed from coleus and roses has to be less than or equal to 117: $0.82x_1 + 1.29x_2 \leq 117$.
5. The number of coleus ($x_1$) must be a whole number.
6. The number of roses ($x_2$) must also be a non-fractional number (implying an integer).

Thus, our symbolic representation in JSON format is:

```json
{
  'sym_variables': [('x1', 'coleus'), ('x2', 'roses')],
  'objective_function': '2*x1 + 9*x2',
  'constraints': [
    '0.82*x1 + 1.29*x2 >= 43',
    '-8*x1 + 8*x2 >= 0',
    '0.82*x1 + 1.29*x2 <= 117'
  ]
}
```

To solve this problem using Gurobi, we will write the following Python code:

```python
from gurobipy import *

# Create a new model
m = Model("Optimization_Problem")

# Define variables
x1 = m.addVar(vtype=GRB.INTEGER, name="coleus")
x2 = m.addVar(vtype=GRB.INTEGER, name="roses")

# Set the objective function
m.setObjective(2*x1 + 9*x2, GRB.MINIMIZE)

# Add constraints
m.addConstr(0.82*x1 + 1.29*x2 >= 43, "growth_speed_min")
m.addConstr(-8*x1 + 8*x2 >= 0, "coleus_roses_ratio")
m.addConstr(0.82*x1 + 1.29*x2 <= 117, "growth_speed_max")

# Optimize the model
m.optimize()

# Print the solution
if m.status == GRB.OPTIMAL:
    print("Optimal solution found:")
    print(f"Coleus: {x1.x}")
    print(f"Roses: {x2.x}")
else:
    print("No optimal solution found")
```