Plant Substitution Under Schedule Pressure
A 1.4-acre urban courtyard renovation is in the planting phase. The contract documents specify 26 multi-stem Amelanchier cultivar 'Autumn Brilliance' at 8-ft height, with a 60-day plant establishment period and substantial completion tied to landscape installation. Three weeks before the planting window closes, the contractor requests substitution to a locally available seedling-grown Amelanchier at a 15% lower unit cost, citing a nursery shortage. The substitution would save $4,200, but the seedling stock is variable in form and has no cultivar guarantee. The owner's representative is pressuring the landscape architect to approve it to protect the opening date, which carries $2,000 per day in liquidated damages under the general contract. The contractor has not submitted photos, nursery tags, or a revised planting schedule.
1. What should the landscape architect do before responding to the substitution request?
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Treat the request as a formal substitution, not a schedule negotiation.
- Re-read the substitution clause and the planting specification; confirm whether the specified cultivar is a performance standard or a closed specification.
- Require the contractor to submit nursery tags, current photos, caliper and height measurements, root-pruning history, and a written availability schedule for both the specified and proposed stock.
- Compare the proposed seedling stock against the design intent: uniform multi-stem form, fall color, disease resistance, and the 60-day establishment warranty. A 15% unit-cost saving does not offset variable form in a courtyard where the trees are the primary spatial element.
- Separate the schedule question from the quality question. Ask for a recovery schedule showing how the specified stock could still be obtained, or what the actual delay would be.
- Respond in writing. If the substitution is denied, state the reason and the resubmittal requirements; do not approve verbally under pressure from the owner's representative.
2. Assume the landscape architect approves a limited substitution. What conditions and documentation should be attached?
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Approve only by written change order with conditions.
- Limit approval to the 26 trees, with a unit price adjustment and a credit of $4,200 or the actual bid difference.
- Require a pre-delivery sample and tag inspection; reject any tree that does not meet the minimum 8-ft height, multi-stem structure, or root-ball standard.
- Maintain the 60-day establishment period and the same replacement warranty.
- Add landscape architect inspection at delivery and at 30 days; increase the replacement contingency because seedling stock is variable.
- State that no time extension is granted unless the contractor proves the specified stock was unavailable despite diligent effort.
- Require the owner's written acceptance of the aesthetic risk. The change order should record that the cultivar guarantee is waived only for the approved stock.
3. Ten of the 26 trees are planted before the landscape architect responds. What actions are appropriate?
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Do not certify the unauthorized planting; control the nonconformance immediately.
- Issue a written nonconformance notice and direct the contractor to stop further planting until the substitution is resolved.
- Inspect and photograph the 10 installed trees; record size, form, root-ball condition, and location.
- Notify the owner in writing. The owner must decide whether to accept the installed trees with a credit or require removal and replacement at the contractor's cost.
- If the trees meet the specification except for cultivar, a conditional acceptance with credit may be reasonable; if they are seedling-grown and variable, removal is more defensible.
- Do not sign the pay application for those trees. Unauthorized work is not automatically a waiver, but silence or payment can weaken the position.
- Document schedule impact separately; the contractor bears the risk of planting before approval.