An unavailable plant does not automatically mean the specification should change. It means the project team needs clearer information: what was searched, which sizes and quantities were checked, what timing is required, and who has authority to review an alternative. Keeping those steps distinct protects both the estimate and the project intent.
01 / Sourcing
Confirm the exact supply question
First verify the botanical name, specified size, quantity, delivery timing and location. A supplier may have the species in a different size, a related cultivar or a limited quantity. Those responses should not be collapsed into a simple available or unavailable label. Ask what was checked and when, and whether the response is a current stock indication, a future production estimate or a firm quote condition.
Check other suppliers where time and scope permit. A single nursery's inventory is not the whole market, although a search across multiple sources still cannot guarantee future supply. Record the supplier and date of the inquiry so a team can decide whether updated confirmation is needed before purchasing.
02 / Sourcing
Keep specified material separate from alternatives
A proposed alternative should be shown as a separate option, with its scientific name, size, quantity, source and any differences identified. Avoid replacing the original schedule row in a working estimate. Keeping both visible helps the estimator and reviewer understand the cost and scope implications without losing sight of the contract requirement.
For restoration work, the review may involve provenance, ecological function, habitat conditions, plant form, timing and project-specific criteria. A species with a similar common name or appearance is not necessarily a suitable ecological substitute. The appropriate designer, environmental professional or contract authority must assess the proposal.
03 / Sourcing
Follow the project's approval process
Tender documents and contracts typically set out how substitutions are requested and approved. Follow that process and submit the information the project team needs: the specified item, the reason for the request, supplier availability evidence, the proposed alternative and any effects on cost, schedule or installation. An estimator can organize the information but cannot grant approval on behalf of the project authority.
Do not assume that silence means approval. Keep written confirmation with the project record and update purchasing documents only after the required approval has been received. If the substitution remains unresolved at bid time, identify the assumption or risk in the estimate in a way that is consistent with the tender instructions.
04 / Sourcing
Revisit pricing and logistics
A different size or source can change unit pricing, freight, handling, availability timing and delivery sequence. A proposed alternative may be less expensive at the nursery gate but require a different quantity, staging plan or maintenance expectation. Compare the full project effect rather than focusing on a single line price.
Availability changes. If procurement is delayed or the planting window moves, refresh the inquiry before committing. A careful substitution review is a documented decision process, not a promise that a replacement will be accepted or delivered.