<PAGE>

                                                                   EXHIBIT 10.13


                                PROMISSORY NOTE

September 29, 1997                                                   $100,000.00


          The undersigned employee of Hines Horticulture, Inc. ("Employee")
hereby promises to pay to the order of Hines Holdings, Inc., a Nevada
corporation (the "Company"), the principal amount of $100,000.00, together with
interest thereon calculated from the date hereof, in accordance with the
provisions of this Note.

          This Note is issued pursuant to a Management Stock Agreement dated as
of the date hereof (the "Management Stock Agreement"), between the Company and
Employee in payment for shares of the Company's Common Stock, par value $.01 per
share (the "Restricted Stock").

          1.   Payment of Principal and Interest.  Interest will accrue on the
unpaid principal amount of this Note from time to time outstanding at a rate per
annum equal to 6.00% from and including the date hereof until and including the
date such principal amount is repaid in full. Employee will pay to the holder of
this Note all principal owing hereunder in three equal payments on April 30,
1998, April 30, 1999 and April 30, 2000 (each, a "Repayment Date").  On each
Repayment Date, Employee shall pay to the holder of this Note all accrued and
unpaid interest, compounded annually on April 30 of each year, on the
outstanding principal amount of this Note. All payments of principal and
interest under this Note shall be made by delivery of cash or checks to the
holder of this Note at the address specified in Paragraph 8 below.

          2.   Prepayments.

          (a) Employee may not at any time voluntarily prepay the outstanding
principal amount of this Note.

          (b) If Employee or any of his Permitted Transferees (as defined in the
Management Stock Agreement) shall sell any shares of Restricted Stock to the
Company, whether pursuant to paragraph 3 of the Management Stock Agreement or
otherwise, the Company may apply this Note in satisfaction of its obligation to
pay Employee or any such Permitted Transferee for such Restricted Stock
purchased by the Company, up to an amount equal to the principal amount
outstanding of this Note, plus accrued and unpaid interest.

          (c) Employee agrees that if Employee or any of his Permitted
Transferees shall become entitled to cash dividends or other cash distributions
on the Restricted Stock, the Company may apply this Note in satisfaction of that
part of its obligation to pay Employee or any such Permitted Transferee for such
cash dividends or other cash distributions up to an amount equal to the
principal amount outstanding of this Note, plus accrued and unpaid interest.

          3.   Acceleration.  Notwithstanding any other provision of this Note
to the contrary, this Note shall become immediately due and payable upon the
transfer of the Restricted Stock in an Approved Sale (as defined in the
Management Stock Agreement).  In the event of such
<PAGE>

a transfer, Employee may satisfy all or a portion of its obligations to repay
the amounts owed hereunder by surrendering shares of Restricted Stock to the
Company. Such shares shall be valued at the sum such shares would otherwise
receive if transferred by Employee in the Approved Sale.

          4.   Security.  All obligations of Employee to the holder hereunder
are secured by a pledge of the Restricted Stock by Employee in favor of such
holder.  Notwithstanding the security provisions of this paragraph, Employee
understands that this Note is a full-recourse note and expressly agrees to and
accepts personal liability for the payment of all principal and interest due the
holder of this Note by the terms of this Note.

          5.   Events of Default.

          (a) Definition.  For purposes of this Note, an Event of Default shall
be deemed to have occurred if (i) Employee fails to pay the outstanding
principal amount plus accrued and unpaid interest on the Note on any Repayment
Date or (ii) Employee breaches any provision of Employee's Management Stock
Agreement.

          (b) Consequences of an Event of Default.   If an Event of Default
shall occur, the holder of this Note may demand, by written notice delivered to
Employee, immediate payment of all or any portion of the outstanding principal
amount of this Note, plus accrued interest thereon. Employee shall pay to the
holder hereof, in addition to all such amounts due, all costs of collection,
including reasonable attorneys' fees.  The holder of this Note shall also have
all of the rights afforded under the Management Stock Pledge Agreement.

          6.   Amendment and Waiver.  Except as otherwise expressly provided
herein, the provisions of this Note may be amended only by the written mutual
consent of Employee and the holder of this Note.

          7.   Cancellation.  After all principal and accrued interest at any
time owed on this Note has been paid in full, this Note shall be surrendered to
Employee for cancellation and shall not be reissued.

          8.   Place of Payment.  Payments of principal and interest are to be
delivered to the holder of this Note at the following address:

                    Hines Holdings, Inc.
                    c/o Hines Horticulture, Inc.
                    12621 Jeffery Road
                    Irvine, California  92720-2199
                         Attention:  Chief Financial Officer

or to such other address or to the attention of such other person as specified
by prior written notice to Employee.

                                       2
<PAGE>

                           *     *     *     *     *

                                       3
<PAGE>

   IN WITNESS WHEREOF, Employee has executed and delivered this Promissory Note
                      as of the date first written above.


                                    /s/ Stephen Thigpen
                                    ---------------------------------------
                                    Stephen P. Thigpen

                                       4